One suggestion I like to give for study/revision is to looks for key words or phrases from the tricky exam questions on our search page: www.saylor.org/search
For example, if I were confused about the "marketing mix" I would search for that phrase or "four parts of marketing mix", etc., then look through the most promising results.
Another approach to this is to use a Google search trick:
site:saylor.org (no spaces) and then your search terms into the Google search box. E.g.
site:saylor.org marketing mix
For some of our textbooks, using
site:saylordotorg.github.io will work.
Our search page, the first link above, allows you to control whether you are searching everything or just textbooks.
It's definitely work, but less labor intensive than trying to guess where in a course or textbook to find what you are looking for.