United States. Office of Education. (1939). Related instruction for plumber apprentices. [s.n.].
Chicago Style (17th ed.) CitationUnited States. Office of Education. Related Instruction for Plumber Apprentices. [Washington]: [s.n.], 1939.
MLA (9th ed.) CitationUnited States. Office of Education. Related Instruction for Plumber Apprentices. [s.n.], 1939.
Warning: These citations may not always be 100% accurate.