Não informado. (1971). Environmental health and safety news. University of Washington, Environmental Research Laboratory.
Citação do estilo Chicago (17ª ed.)Não informado. Environmental Health and Safety News. Seattle, Wash: University of Washington, Environmental Research Laboratory, 1971.
Citação MLA (8ª ed.)Não informado. Environmental Health and Safety News. University of Washington, Environmental Research Laboratory, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.