Look at the reference list at the end of a good article or book to see what that author consulted. Then search to see if we have that item. Or look for other articles/books published by that person - academic authors tend to publish in specialized areas of research.
Finding a known article
If you have the complete citation (i.e. author, title of article, journal title, volume, pages, year) you can quickly find the article using one of these strategies.
Try putting this article title into Google Scholar, with and without quotation marks, to see the difference: Gillen, A., Wright, A., & Spink, L. (2011). Student perceptions of a positive climate for learning. Educational psychology in practice, 27(1), 65-82.
Still can't find it?
Browse the 'classic catalogue' for the journal title, or go directly to this page.