Heyel, C., & Heyel, C. (1972). Handbook of modern office management and administrative services. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Heyel, Carl, agus Carl Heyel. Handbook of Modern Office Management and Administrative Services. New York: McGraw-Hill, 1972.
Lua MLA (9ú heag.)Heyel, Carl, agus Carl Heyel. Handbook of Modern Office Management and Administrative Services. McGraw-Hill, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.