Crumb, C. V. (1970). Training people effectively: The teaching manual for instructors and supervisors in business, education, industry and the professions. Lefax Pub.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Crumb, Charles V. Training People Effectively: The Teaching Manual for Instructors and Supervisors in Business, Education, Industry and the Professions. Philadelphia, Pa: Lefax Pub, 1970.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Crumb, Charles V. Training People Effectively: The Teaching Manual for Instructors and Supervisors in Business, Education, Industry and the Professions. Lefax Pub, 1970.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.