When you already have the title, author and journal information for an article there are several ways to easily locate the article using Google Scholar and the Adler Library catalog:
Backward citation chasing means looking at the sources cited within your article-in-hand.
Authors use sources to build arguments, so it makes sense to investigate the sources that authors used to support their arguments.
Let's take a look at the example below...
Miller, M. J., Sendrowitz, K., Connacher, C., Blanco, S., de La Pena, C. M., Bernardi, S., & Morere, L. (2009). College students’ social justice interest and commitment: A social-cognitive perspective. Journal of Counseling Psychology, 56(4), 495.
This journal article is about the development of social justice interest and commitment in college students.
In the abstract of the article, the authors say they use the "social-cognitive career theory" developed in 1994 by Lee, Brown, & Hackett.
If I'm interested in this theory, I may want to read the work written by Lee, Brown, & Hackett.
I can go down to the references at the end of the article, locate the correct citation by Lee Brown, & Hackett and find the full-text to this source.
In this sense, we're going backward in time--seeing the sources that our original author (Miller) used, which is why we call this backward citation chasing.