How to fly; the pilot and his problems,

A development from the author's Flight school manual of the Naval air station at Pensacoln, Fla., written in 1926, later revised and published in 1928 under title: Practical flight tranining.

Sociology and ethics; the facts of social life as the source of solutions for the theoretical and practical problems of ethics,

Mode of access: Internet.

Nationality and its problems,

Mode of access: Internet.

The manual of chess: containing the elementary principles of the game; illustrated with numerous diagrams, recent games and original problems.

Mode of access: Internet.