Teilhard de Chardin, P. (1973). On happiness ([1st U.S. ed.].). Harper & Row.
Lua i Stíl Chicago (17ú heag.)Teilhard de Chardin, Pierre. On Happiness. [1st U.S. ed.]. New York: Harper & Row, 1973.
Lua MLA (8ú heag.)Teilhard de Chardin, Pierre. On Happiness. [1st U.S. ed.]. Harper & Row, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.