National Safety Council. (1956). Supervisors safety manual; better production without injury and waste from accidents. s.n.
Chicago-referens (17:e uppl.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. Chicago: s.n, 1956.
MLA-referens (9:e uppl.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. s.n, 1956.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.