Citations to the publications could not be added manually. That publication should be uploaded into ResearchGate and then it will be added to citations to particular articles.

Why are some of my citations not shown?

While citations using standard citation styles are usually extracted accurately on ResearchGate, there are some instances where they cannot be extracted – for example, for full-text PDFs that have been created from scanned hard copies. PDF as a format is not particularly standard, and therefore creating algorithms to extract this information is an ongoing process, with varying levels of success. Please also note that citations that do not have complete metadata (publication date, journal, abstract) may not be included in your citation counts, as this is an important piece of information when it comes to matching citations to publications correctly. Our citation data is regularly updated and we are working hard to improve how we extract and match citations, so if you notice some are missing, they may be added soon.

Why did my citation count decrease?

There are two possible reasons why your citation count or h-index decreased. It is possible that you were cited by a publication which was duplicated in our system. We then merged the duplicates which resulted in the loss of a citation. Alternatively, an author of a publication which cited you may have removed their publication from our database entirely. Since there are over a billion citations in our database, we cannot further investigate the cause of any particular fluctuation in citation count or h-index. 

you can delete the article which you need to add its citation and upload a version from the publisher again again