Citation Searching means using a specific article, usually a key article on that topic, to find other articles that built on the work done in the key article - i.e articles that cite the key article.
So, say you were researching Estrogen and Memory, and your professor told you that this article :
Estrogen actions throughout the brain
Author(s): McEwen B
Source: RECENT PROGRESS IN HORMONE RESEARCH, VOL 57 Book Series: RECENT PROGRESS IN HORMONE RESEARCH Volume: 57 Pages: 357-384 Published: 2002
was an extremely important article in this area. To find the articles that follow up work done since this article came out, you can do a citation search in Web of Knowledg. To do that, follow these steps. We'll use this article as our example, but you would use the information from whatever article you are wanting to do the citation search on.
1. Go to Web of Knowledge (Web of Science)
2. Click on the "Cited Reference Search" tab
3. Enter the Author name - put last name first then a space and then the first initial followed by an asterix - McEwen B*
4. Look up the journal title in their journal title abbreviation list and jot that down - in this case it is
RECENT PROG HORM RES
5. Type in the journal title abbreviation in the Source Box
6. Type the publication year in the years box - in this example that is 2002
7. Search
Then you'll get a screen that looks something like this, with the options for what might be your article. You want to choose all that seem to be the right one. The reason more than one is listed is because some people make slight changes in their citations and so may use slightly different wording to cite the same article. You check the ones you want and then click to finish the search.
Then your results will be all the articles that cite your article. You can then sort those results by Date or by how many times they have been cited themselves, thus ranking them in importance.