The UGA Libraries has nearly 6 million books available for you to use. Some of these books are academic in nature, and some are popular. They don't all go through the same editorial process as scholarly research articles. When doing research, make sure the book you're using is rigorous. There are ways to do this:
1) Who published the book? If the book is published by a University Press, then it most likely went through an extensive editorial process.
2) Who wrote the book? Academic books are written by experts in a field. Don't know how to find this out? Google the name of the author or look at the bio blurb for the book. Are they a researcher in this subject? Are they affiliated with a University or Research institute?
3) What was the audience? Academic books are written for other academics, or for students studying a particular subject.
If it isn't a book published by an academic press, written by an expert in a field, and was written with other experts in mind, don't use the book for this assignment.