Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
H. G. Wells
Lyn Venable
Thomas Hoover
Carl R. Maag and Steve Rohrer
United States. Arms Control and Disarmament Agency
United States. Department of the Army
Murray Leinster
Edson McCann
John J. McGuire and H. Beam Piper
George O. Smith
Noel M. Loomis
Lowell Stone
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.