Also consider that this question, or a close variant of it, gets asked about once every 2-3 weeks or so. Using the search feature and searching for "math book" or "math study" or something similar should turn up loads of previous discussion on this topic.
https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...