Gray, W. S. (1930). The training of college teachers, including their preliminary preparation and in-service improvement. The University of Chicago press.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Gray, William Scott. The Training of College Teachers, Including Their Preliminary Preparation and In-service Improvement. Chicago, Ill: The University of Chicago press, 1930.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Gray, William Scott. The Training of College Teachers, Including Their Preliminary Preparation and In-service Improvement. The University of Chicago press, 1930.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.