Mathematics changes very slowly, so old books are just as good as newer ones. Up to the graduate level, you really don't need new books. I recommend the Dover

Mathematics changes very slowly, so old books are just as good as newer ones. Up to the graduate level, you really don't need new books. I recommend the Dover Books on Mathematics series: http://www.amazon.com/s/ref=nb_sb_ss_c_0_25?url=search-alias%3Dstripbooks&field-keywords=dover+books+on+mathematics http://www.amazon.com/s/ref=nb_sb_ss_c_0_25?url=search-alias...