Proctor, W. M. (1929). Vocations: The world's work and its workers. Houghton Mifflin Company.
Lua i Stíl Chicago (17ú heag.)Proctor, William Martin. Vocations: The World's Work and Its Workers. Boston : New York [etc.]: Houghton Mifflin Company, 1929.
Lua MLA (8ú heag.)Proctor, William Martin. Vocations: The World's Work and Its Workers. Houghton Mifflin Company, 1929.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.