Kranzberg, M., & Gies, J. (1975). By the sweat of thy brow: Work in the Western world. Putnam.
Lua i Stíl Chicago (17ú heag.)Kranzberg, Melvin, agus Joseph Gies. By the Sweat of Thy Brow: Work in the Western World. New York: Putnam, 1975.
Lua MLA (9ú heag.)Kranzberg, Melvin, agus Joseph Gies. By the Sweat of Thy Brow: Work in the Western World. Putnam, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.