Não informado. (1987). Safety and health at work. International Occupational Safety and Health Information Centre.
Lua i Stíl Chicago (17ú heag.)Não informado. Safety and Health at Work. Geneva, Suíça: International Occupational Safety and Health Information Centre, 1987.
Lua MLA (8ú heag.)Não informado. Safety and Health at Work. International Occupational Safety and Health Information Centre, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.