Books for self-study in "pure areas" of mathematics Hi, I am starting an applied mathematics course this year at university. Unfortunately I don't have the option to study "pure" areas of mathematics, but I would like to learn more about them to become a more complete mathematician at the end of the course, as I understand that areas such as topology also have important practical applications and also because of my intelectual curiosity. Therefore I would like to know if you guys could recommend good books for self study in topology, graph theory, number theory and group theory, or any other "purer" area that I may be forgetting and you think is important/interesting. I like books that have many examples or worked problems but also present proofs. I recently studied linear algebra using Gilbert Strang's video lectures and David Poole's book, and I thought this was a good method and the syllabus was of sufficient depth and difficulty for my current conditions, so I believe this would be the level I am looking for (first years of undergradute school). Thanks for your help!