Von Richthofen, W. (2002). Labour inspection: A guide to the profession. International Labour Office.
Lua i Stíl Chicago (17ú heag.)Von Richthofen, W. Labour Inspection: A Guide to the Profession. Geneva: International Labour Office, 2002.
Lua MLA (9ú heag.)Von Richthofen, W. Labour Inspection: A Guide to the Profession. International Labour Office, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.