Cita APA (7a ed.)

(1955). Keys to happiness: A Reader's Digest guide to successful living. The Reader's Digest Association.

Cita Chicago Style (17a ed.)

Keys to Happiness: A Reader's Digest Guide to Successful Living. The Reader's Digest Association, 1955.

Cita MLA (9a ed.)

Keys to Happiness: A Reader's Digest Guide to Successful Living. The Reader's Digest Association, 1955.