Não informado. (1939). Supervision: The magazine of industrial relations and operating management. National Association of Foremen.
Chicago-viite (17. p.)Não informado. Supervision: The Magazine of Industrial Relations and Operating Management. Burlington, Vt: National Association of Foremen, 1939.
MLA-viite (8. p.)Não informado. Supervision: The Magazine of Industrial Relations and Operating Management. National Association of Foremen, 1939.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.