See: https://www.researchgate.net/post/How_to_find_citations/1

http://www.ncbi.nlm.nih.gov/pubmed

After searching for a title you can find on the right side a topic "cited by"

another way would be OVID but for this you need an account

You can also directly use Research Gate for looking up citation information. Enter the title of the paper into the search bar. Then on the right side select 'Publications'. Usually the first hit is the paper you searched. Click onto the title and the information page will appear. At the bottom you will find 'Cited in (X)'. 

Hi, you can try search any relavant journals in PubMed.

Mr. Aphkhazava ..!

Please visit My Citations under GOOGLE SCHOLAR. It will provide all the information about citations, h-index and i10 index.

http://scholar.google.co.in/schhp?hl=en

You could certainly search citation using google scholar. In my humble opinion, it is the best available site. The other option would be "scopus" and "web of science". 

http://www.scopus.com/

http://incites.isiknowledge.com/Home.action

You can create an acoount for google scholar citations and also get citation alert or you can use web of science but google scholar is updated and  best one!! Researchgate doesn't show your  all citations.

google scholar citation...perfect...have to create an account for yourself and organize your publications first, from there, it is regularly updated

You can also use web of Science of Scopus.

Moreover, many journal provide in online version alos list of the article what cited given article.

Google scholar, also Web of science (Thompson reuters). Google scholar shows some duplicate entries in some cases. 

Web of science

Yes, Web of science; URL

http://apps.webofknowledge.com/UA_GeneralSearch_input.do?product=UA&search_mode=GeneralSearch&SID=2FWV7jyXDasLybaJ5TL&preferencesSaved=

here you can use keywords to search and view your list of articles. It also creates a whole different types of statistics (charts) that can be downloaded as text file of to the endnote.

Also Google scholar website is efficient for ascertaining citation of any paper. Is good if you register so you can also see those who cited your paper. 

In Google scholar. You can register there and check the citation, index h and index i10 as well.

many thanks

scopus will give accurate results.