Chellew, H. (1920). Human and industrial efficiency. G. P. Putnam's Sons.
Lua i Stíl Chicago (17ú heag.)Chellew, Henry. Human and Industrial Efficiency. New York, London: G. P. Putnam's Sons, 1920.
Lua MLA (8ú heag.)Chellew, Henry. Human and Industrial Efficiency. G. P. Putnam's Sons, 1920.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.