Use Google Scholar for citation tracking to see who has cited a work.
In this search for the article "The Amphibian Tree of Life," note the Cited by link beneath the abstract. Clicking "Cited by 1494" would direct you to a list of articles that cited this article.
EndNote Basic (Web) is a web-based tool for managing and citing references in papers and creating bibliographies.
The resources listed here assist in assessing the impact of articles, journals, and researchers.