Não informado. (2011). Work Study & Management Services. Institute of Practitioners in Work Study, Organization and Methods.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Work Study & Management Services. Middlesex, Inglaterra: Institute of Practitioners in Work Study, Organization and Methods, 2011.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Work Study & Management Services. Institute of Practitioners in Work Study, Organization and Methods, 2011.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.