Ladd, G. T. (1894). Psychology, descriptive and explanatory: A treatise of the phenomena, laws, and development of human mental life. C. Scribner's sons.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ladd, George Trumbull. Psychology, Descriptive and Explanatory: A Treatise of the Phenomena, Laws, and Development of Human Mental Life. New York: C. Scribner's sons, 1894.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Ladd, George Trumbull. Psychology, Descriptive and Explanatory: A Treatise of the Phenomena, Laws, and Development of Human Mental Life. C. Scribner's sons, 1894.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.