(1955). Keys to happiness: A Reader's Digest guide to successful living. The Reader's Digest Association.
Lua i Stíl Chicago (17ú heag.)Keys to Happiness: A Reader's Digest Guide to Successful Living. The Reader's Digest Association, 1955.
Lua MLA (9ú heag.)Keys to Happiness: A Reader's Digest Guide to Successful Living. The Reader's Digest Association, 1955.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.