National Safety Council. (1956). Supervisors safety manual; better production without injury and waste from accidents. s.n.
Chicago-Zitierstil (17. Ausg.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. Chicago: s.n, 1956.
MLA-Zitierstil (9. Ausg.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. s.n, 1956.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.