United States Bureau of Labor Standards. (1951). Occupational outlook handbook: Employment information on major occupations for use in guidance. United States. Government Printing Office.
Lua i Stíl Chicago (17ú heag.)United States Bureau of Labor Standards. Occupational Outlook Handbook: Employment Information on Major Occupations for Use in Guidance. Washington, D.C: United States. Government Printing Office, 1951.
Lua MLA (9ú heag.)United States Bureau of Labor Standards. Occupational Outlook Handbook: Employment Information on Major Occupations for Use in Guidance. United States. Government Printing Office, 1951.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.