Não informado. (1985). National safety and health news. National Safety Council.
Chicago-referens (17:e uppl.)Não informado. National Safety and Health News. Chicago, Ill: National Safety Council, 1985.
MLA-referens (8:e uppl.)Não informado. National Safety and Health News. National Safety Council, 1985.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.