Não informado. (1973). Job safety and health. Occupational Safety and Health Administration.
Citação do estilo Chicago (17ª ed.)Não informado. Job Safety and Health. Washington: Occupational Safety and Health Administration, 1973.
Citação MLA (8ª ed.)Não informado. Job Safety and Health. Occupational Safety and Health Administration, 1973.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.