Suppose you are investigating theories on the possibility of past life on Mars. You know a journal article on the subject:

D.S. McKay, E.K. Gibson, et al."Search for past life on Mars: Possible relic biogenic activity in Martian meteorite ALH84001." Science. Volume 273 Number 5277, pages 924-930, August 16, 1996.

Using the Science Citation Index, you can find recently published journal articles that cite the article by D.S. McKay et al..

Open the citation database(s) you wish to search. This sample search was performed using the 1997 Science Citation Index with Abstracts compact disc edition.