Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Oswald Veblen and N. J. Lennes
Arthur Latham Baker
Felix Klein
G. H. Hardy
Jacques Hadamard
Maurice Godefroy
Ernst Leonard Lindelöf
Charles Henry
Karl Weierstrass
Charles Briot and M. Bouquet
Karl Joseph Bobek
Leo Koenigsberger
Friedrich Schottky
These books are free to read. Each is in the public domain in the United States; check your own country's rules before you copy or share one.