You may consider it as a forum discussion. An example for forum as given by Purdue University (APA format)

"Online Forum or Discussion Board Posting Include the title of the message, and the URL of the newsgroup or discussion board. Please note that titles for items in online communities (e.g. blogs, newsgroups, forums) are not italicized. If the author's name is not available, provide the screen name. Place identifiers like post or message numbers, if available, in brackets. If available, provide the URL where the message is archived (e.g. "Message posted to..., archived at...")."

See an example here:

Saini, Debi (2014, May 26). What are the best methods to introduce concepts of sustainability to all? [Msg 11]. Message posted at https://www.researchgate.net/post/What_are_the_best_methods_to_introduce_concepts_of_sustainability_to_all

https://owl.english.purdue.edu/owl/resource/560/10/

You may consider it as a forum discussion. An example for forum as given by Purdue University (APA format)

"Online Forum or Discussion Board Posting Include the title of the message, and the URL of the newsgroup or discussion board. Please note that titles for items in online communities (e.g. blogs, newsgroups, forums) are not italicized. If the author's name is not available, provide the screen name. Place identifiers like post or message numbers, if available, in brackets. If available, provide the URL where the message is archived (e.g. "Message posted to..., archived at...")."

See an example here:

Saini, Debi (2014, May 26). What are the best methods to introduce concepts of sustainability to all? [Msg 11]. Message posted at https://www.researchgate.net/post/What_are_the_best_methods_to_introduce_concepts_of_sustainability_to_all

https://owl.english.purdue.edu/owl/resource/560/10/

As Nageswara Rao said. Alternatively; the guidelines for citing "personal communications" may fit there. While i do not think that it is forbidden to cite RG comments, i would keep in mind that while contentwise can be reliable sources, they are not stable contents and can be modified or deleted any time.

Find valuable answers to this question here in this thread :)

https://www.researchgate.net/post/How_do_you_acknowledge_valuable_answers_by_RG_peers_in_your_papers

The best way to cite a ResearchGate comment is to see it as a personal communication. This is because comments are personal views of the contributors or individuals. To therefore reference a comment or personal communication, in-text citing is only needed and no reference citation.

Consider the examples below:

 According to N. R. Posinasetti (personal communication, June 13, 2014), in the absence of the author’s name, the screen name should be provided.

 The guidelines for referencing personal communications can fit in for ResearchGate comments (J. Toth, personal communication, June 13, 2014).

 (M. Bruckner, personal communication, June 13, 2014) or M. Bruckner (personal communication, June 13, 2014).

The format here is:

The initial first, Surname second, personal communication third, and the month, date and year last.

I think yes you can by saying for instance according to X (200X) "abc...".

The question is an all-important one. I have already cited some useful information from RG to support my argument in a paper i am currently writing. I agree that comments from RG can be referenced as personal communication, and that is what I have done.

Dear Nageswara, thanks for the valuable statement. I agree with you....

Respected Nageswara Rao Posinasetti, thanks for serving a detailed reply. I agree to it. But what about copy rights? Do you think it would not be a problem.

Nagerwara Rao, thanks a lot for your valuable remarks concerning citations of the RG form memmbers. I'm just getting ready to cite in my following paper a few persons' "utterances'"and you've showed me a very precise way.

Dear Asmat

The question of copyright does not come here because we are quoting directly with reference. Anything quoted directly be within quotation mark and a reference.

Very useful thread, the quotes as personal communication would be appropriate I feel and fully agree with Nageswara Rao Posinasetti, that there are no copyright issues involved here.

I think that Professor Nageswara Rao Posinasetti has said it all, for sure.

Sometimes, I see outstanding contributions, in my opinion, in RG. Utilization of them is very good for various sciences & the mechanism of citation could be done as the Professor explained.

Respected Nageswara Rao Posinasetti,

Sir, thanks for clearing my doubts.

Here is an example of a paper that quotes a lot of threads from RG.

I think that the best ways is to insert as personal communication, maybe couplet to a special acknowledgments at the end of the paper/thesis

@Nageswara: Thank you for referring to the paper where RG Q&A sections are quoted, and for referring to the APA style guide incl. a particular example! I am glad that social networking is now officially accepted in standards and that people appreciate and incorporate online discussions into their research. I was surprised enough to notice that (my) blog posts were quoted in research papers, so this step is one more in the right direction! I hope to see more papers (and from different areas) quoting online discussions and encounters. In the meantime, my advice is to annotate and archive information you find useful - social networks change, users, posts and whole social or blogging platforms may disappear.

As blog articles are cited, that is, by giving URAL. Since ResearchGate on a thread has several responses, therefore, to refer a scholar/scientist response have to mention his/her name and also date as a person may have written several interrelated responses apart from giving thread's link.

In a progressive research, citing is an important feature of the research....In a literature survey which is the prime part of knowledge source for a research project.

Citing recognizes both the researcher and the fore-runner for search on the same project. It creates a positive teaming of intellectual search -seek - satisfaction .

Krishnan,@ What an intereting diagram! Thanks a lot. It'll be very helpful in writing about my research.

@ Janina

Best wishes to your research... this model forms part of the article (in the process) titled manufacturing KM - data science.

Krishnan@, a diagram to think about when I get bogged down in APA format. My thoughts, beyond giving credit to the originator......we are living in an age of information explosion. With this kind of growth, there will be growing pains in citations. Following old digital links can be a problem; and for those interested in historical information, the DOI number becomes very important. With the current ease of translations, I think we need to look at an international uniform citation methodology-it is the right thing to do!

@ Roberta

I agree with you on the retrieval and traceability through DOI etc.....

IT age has given more pro and cons to citation... many a times there are more stringent protections a creator of a Knowledge resource needs to do it.....

Please the enclosed link to infer the protection on Knowledge resources is also increasing...

Data Framework - Manufacturing KM Data Science

Krishnan@ once again, many thanks. Your sort of reasoning speaks to my mind and i find it very helpful.

Regarding this issue, I also consider that a reasonable and effective solution may be of the nature of a "personal communication", which has been floated above in a response, conveying a significant point, either as a conjuncture or an experimental observation (some times as unpublished information). Permission from the presumed originator in Research Gate is must, as accreditation is of paramount importance, particularly in the age of, to use informal terminology, "reinventing the wheel". Certain comments here, at RG forums, appear to be informative and insightful, as voiced above.

@ Chithan - Obtaining permission is correct....

At time during literature survey, citing a research could be confusing in a similar research area (where some inputs or concepts or finding could be common)

It is an intriguing idea!

 Krishnan : Thank you.

I do appreciate your point.  As far as the endeavor of science, and associated conventions are concerned, investigators usually would have left no stone unturned, and would have striven to uncover all possible citations at a time when literature searches were laborious and were manually performed some three decades ago. We find the issue of assigning prior observation or accreditation becoming thorny, paradoxically with the voluminous mining resources on hand at unparalleled levels. Immunology at least is an area where this had perpetuated; looking at certain cases, accreditation, most soberly and woefully,   had possibly become anathema, even though the process is a coping stone in the dissemination of information.  

Reginald – I have articulated a position above for your question of prior permission from the originator (regarding ascribing ideas, reasoning and theorization, and philosophy, to the presumptive originator in question ; similar is the proposition advanced by certain individual (s) here, preceding my anwer. I presume that this might be shared by several membes.  To wit, words fewer than one may be of enormous significance indeed (two words, “hydrated form”, would be making a  world of difference in the nexus of the three dimensional structure of DNA).  Thank you.

@ Chithan, Fully agree with you on "find the issue of assigning prior observation or accreditation becoming thorny, paradoxically with the voluminous mining resources on hand at unparalleled levels"

Thank you very much Chithan. Moreover, everyone's posts have been very helpful. Given the fluid changes to ResearchGate, citing authors who post ideas seems to be an evolving challenge.

I fully agree to cite important ideas that researchers do at ResearchGate and other social networks, are indisputable sources of knowledge and they should be regulated in all styles like APA, Harvard, Chicago, Vancouver, etc. 

I agree with the Nageswara Rao Posinasetti example citation:

Saini, Debi (2014, May 26). What are the best methods to introduce concepts of sustainability to all? [Msg 11]. Message posted athttps://www.researchgate.net/post/What_are_the_best_methods_to_introduce_concepts_of_sustainability_to_all

Fragment from: Purdue OWL: APA Formatting and Style Guide

Online Forum or Discussion Board Posting

Include the title of the message, and the URL of the newsgroup or discussion board. Please note that titles for items in online communities (e.g. blogs, newsgroups, forums) are not italicized. If the author's name is not available, provide the screen name. Place identifiers like post or message numbers, if available, in brackets. If available, provide the URL where the message is archived (e.g. "Message posted to..., archived at...").

Frook, B. D. (1999, July 23). New inventions in the cyberworld of toylandia [Msg 25]. Message posted to http://groups.earthlink.com/forum/messages/00025.html

If you talk about some one, you cite it as "Al-Rawajfeh, private communication", so I suggest to cite it as "Al-Rawajfeh, RG commumication, June 2nd, 2014"

Could we write it as personal communication?

Dear Kamal and Jaleed, I  agree with your statement that it could be written as personal communication.

Though there is nothing wrong in quoting it as Personal Communication, it will not provide an opportunity for the reader to visit and get further details from that communication. As an online forum citing method helps the people to visit and explore further. The only problem is if the thread is available in RG or not. How long RG will keep them available after all interest in the thread disappears is a question that need to be answered by RG?

This is true because authors can edit and delete comments at any time. This is problematic for citations from a ResearchGate thread, unless there is a way to archive and make permanent a comment made within a thread.

That is a good point Dear Kamal and Reginald. May we can update the reference by specifying the date of access. At least that makes the author true. If the comment modified or deleted later the author is not responsible.

Saini, Debi (2014, May 26). What are the best methods to introduce concepts of sustainability to all? [Msg 11]. Message posted at https://www.researchgate.net/post/What_are_the_best_methods_to_introduce_concepts_of_sustainability_to_all; Accessed on June 13, 2014.

I agree your point as the same @ Kamal Eddin Bani-Hani & Reginald L. Bell. 

Kalpana R. @ I absolutely agree with you concerning Kamal and Reginald L. Bell

I agree the same; and add: be careful, even RG can delete some writing which is not in the norm after certain time..

You can see for example, sometimes one number of questions for an RG member, and, when you try to accede to all questions, you find that one or two are hidden !

Maybe like an personal comunication (APA), be a simple and universal form.  Because is just one commnet or one author. 

Keep the title of the threads  permanently available online. Authors can then include the title and URL as part of bibliographical data. Content may be updated. 

Only through sources of publication, (sources of publication, authors and title ...!

I  concur with Dr.Nageswara. Thanks for useful post.

This will be good for you: https://teachbytes.com/2013/04/09/how-to-cite-social-media-mla-apa-formats/

thank you for all for nice information

I recommend to use as online forum and discussion. It is customer these days many forums available online and they are a good sources of information.

Interesting question!

I would recommend against citing Research Gate. Personal communication with the author of the idea would be far better. Better still would be a reputable source (i.e., an academic document published in a highly regarded journal or book).

Cam

I don't think that the RG is suitable to be a reference for a scientific work. I recommend that it should be only personal communication. This comment is a guide for the future work only but cannot be a reference. If we consider the comments as a reference, we should consider the comments of reviewers as a reference also.

It was just pointed out to me that this question existed already. This was something I had also wondered about 2 years ago (https://www.researchgate.net/post/What_is_the_proper_way_to_cite_contributions_made_to_a_Research_Gate_question?view=5b0eadbec68d6b6a3e3f0285). I have since published papers and used the following format to cite the discussion/question in the text, but not as part of the bibliography, "(contributor name1; contributor name2, personal communication, year)”.

Nice question, I usually cite the URL as well

I also would recommend against citing Research Gate.

Research leading to innovation may be with standard references is suitable for Research Gate.

I like the discussion. Now there are two camps: those for citing RG and those against. RG is a platform for academics and scholars from varied disciplines, and so I think their views are worthy of citation into any academic publication. Increasingly, I see writers cite from Wikipaedia. And I rate RG over and above Wikipaedia in terms of quality and credibility of information. I therefore think that, what matters, as has been asked, is the best way to cite from RG.

Every body may generalized some concept and idea from comments and discussion of Research gate and ln research.paper standard references related to this discussion may be presented in the paper..

Dear, extract the detail of the authours, volume, issue, page numbers of the Journal that published the work and follow the style of the Journal you want to submit your paper to make your reference.

The focus of academic writing should be citations and references to other scholarly peer-reviewed work. Obviously, it is also sometimes appropriate to cite other sources, particularly for factual information.

If a RG comment is really only an inspiration, maybe it is better to go find a peer-reviewed source for the same idea, now that your RG friend has called your attention to it.

Page 215 of the APA manual 6th edition uses this example:

Smith, S. (2006, January 5). Re: Disputed estimates of 0 [Electronic mailing

list message]. Retrieved from http://tech.groups.yahoo.com/group

/ForensicNetwork/message/670

I think you could replace "electronic mailing list message" with "online forum post" or "Researchgate forum post."

www.citationmachine.com

You may use one of the most popular four citation methods like APA.

I agree with Michael W. Marek.

Sir, I cant open your given link. Emad Kamil Hussein

my friend who uploaded his papers on the research gate has so many citations but I have no citation although I also upload all my papers. we are from same hospital and only little difference in all articles , kindly guide me what should I don ,

Abbas Nasir , Emad Kamil Hussein and others: unfortunately the cited link >www source www. (citationmachine) .com < - used / applied / accessed directly from my iPhone signalized a potent dangerous site (insinuating infection by virus and destroying the operating system. I am able to communicate this after some minute, so i do hope that my iPhone system has been protected sufficiently from viral infection... This said/written only to warn others to try the link... shall see what happens when trying to access by means of more severely protected PC....

Again, to Emad Kamil Hussein , Abbas Nasir and others: when clicking the above mentioned website [www. (citationmachine) .com] using my well protected home-PC i ended up with

which purports to belong to 'ZEIT-Online' in its headline (otherwise a serious kind of online-journal) but tries to persuade visitor to take part in big money-making/earnings investing into BIT-coin(s)... I'd rather aadvise anybody against to do so....(;-||

Check for the semblance of that comment with some published research work of the comment maker or other researcher to cite.

Here is a source that I trust.

it can be adapted to other citation styles but this one is APA-

https://library.purdueglobal.edu/writingcenter/apacitationfordiscussionpost

I have been doing the following, and it seems to work: Enter the comment as a quotation into your text followed by a reference marker, e.g., a number or author and date. In the references, fill in the author, date, and title (if these exist) similar to a standard citation for a scientific paper, followed by the link shown by ResearchGate to the specific entry. When you are finished, copy the link into Word, etc., and test the link to be certain the link takes the reader to the proper location.

Alternatively, cite the quotation as a "personal communication," which is not acceptable in some journals.