Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Steve Solomon and Isabel A. Moser
W. B. O'Shaughnessy
Edward J. Van Liere
Wm. H. Fitzgerald and Edwin F. Bowers
F. W. Beneke
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.