University of Illinois (Urbana-Champaign campus). Bureau of Economic and Business Research. (1930). A test analysis of unsuccessful industrial companies. University of Illinois.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)University of Illinois (Urbana-Champaign campus). Bureau of Economic and Business Research. A Test Analysis of Unsuccessful Industrial Companies. Urbana: University of Illinois, 1930.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)University of Illinois (Urbana-Champaign campus). Bureau of Economic and Business Research. A Test Analysis of Unsuccessful Industrial Companies. University of Illinois, 1930.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.