Não informado. (1939). Supervision: The magazine of industrial relations and operating management. National Association of Foremen.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Supervision: The Magazine of Industrial Relations and Operating Management. Burlington, Vt: National Association of Foremen, 1939.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Supervision: The Magazine of Industrial Relations and Operating Management. National Association of Foremen, 1939.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.