United States. Division of Labor Standards. (1938). Putting national plumbing apprenticeship standards to work: A manual of procedure for establishing local joint plumbing apprenticeship standards. [s.n.].
Chicago Style (17th ed.) CitationUnited States. Division of Labor Standards. Putting National Plumbing Apprenticeship Standards to Work: A Manual of Procedure for Establishing Local Joint Plumbing Apprenticeship Standards. [Washington]: [s.n.], 1938.
MLA (9th ed.) CitationUnited States. Division of Labor Standards. Putting National Plumbing Apprenticeship Standards to Work: A Manual of Procedure for Establishing Local Joint Plumbing Apprenticeship Standards. [s.n.], 1938.
Warning: These citations may not always be 100% accurate.