Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Vatsyayana
Mary Wollstonecraft
John Stuart Mill
Havelock Ellis
Anonymous
Stendhal
John Harvey Kellogg
B. G. Jefferis and J. L. Nichols
Otto Weininger
comte de Honoré-Gabriel de Riqueti Mirabeau
H. L. Mencken
Iwan Bloch
Hans Fehlinger
Sarah Grimké
Thomas W. Shannon
Mary Astell
D. Ph. van Vloten Elderinck
Various
August Bebel
Catharine Esther Beecher
H. W. Long
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.