Goldstein, K., & Scheerer, M. (1950). Abstract and concrete behavior: An experimental study with special tests. The American Psychological Association, Inc., Northwestern University.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Goldstein, Kurt, و Martin Scheerer. Abstract and Concrete Behavior: An Experimental Study with Special Tests. Evanston, Illinois: The American Psychological Association, Inc., Northwestern University, 1950.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Goldstein, Kurt, و Martin Scheerer. Abstract and Concrete Behavior: An Experimental Study with Special Tests. The American Psychological Association, Inc., Northwestern University, 1950.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.