PAPER FOLDING MATH PEOPLE
Score of a lifetime: library book sale had a pile of unwanted math books. So I buy them and when I get them home I see most belonged to noted mathematics author Leo F. Boron!
He authored books on math and translated many more. The best part besides his notes, signatures and ex-libris bookplate: a paper polygon tucked inside of one of the books. It's a regular pyramid made from green construction paper.
I also snagged a book once owned by noted University of Michigan professor George Kish. Is the third edition of Burlington's "Mathematical Tables and Formulas". The papers of Professor George Kish are now in the archives of the Bentley Historical Library in Ann Arbor Michigan...well, at least the ones that aren't on my bookshelves.