Cita APA (7th ed.)
(1961). Bulletin... United States Department of Labor. Bureau of Apprenticeship and Training.
Cita Chicago (17th ed.)
Bulletin... United States Department of Labor. Bureau of Apprenticeship and Training. Washington, 1961.
Cita MLA (9th ed.)
Bulletin... United States Department of Labor. Bureau of Apprenticeship and Training. 1961.
Atenció: Aquestes cites poden no estar 100% correctes.