Chicago: 
								 "The Language-Families of Africa," The Language-Families of Africa in  Primitive Behavior: An Introduction to the Social Sciences, ed. Thomas, William I. (New York: McGraw-Hill Book Company, Inc., 1937), Original Sources, accessed November 3, 2025, http://www.originalsources.com/Document.aspx?DocID=TCKPFQAWF2SBLKI.
								
							
							
								MLA: 
								. "The Language-Families of Africa." The Language-Families of Africa, in  Primitive Behavior: An Introduction to the Social Sciences, edited by Thomas, William I., New York, McGraw-Hill Book Company, Inc., 1937, Original Sources. 3 Nov. 2025. http://www.originalsources.com/Document.aspx?DocID=TCKPFQAWF2SBLKI.
								
							
							
								Harvard: 
								, 'The Language-Families of Africa' in The Language-Families of Africa. cited in  1937, Primitive Behavior: An Introduction to the Social Sciences, ed. , McGraw-Hill Book Company, Inc., New York. Original Sources, retrieved 3 November 2025, from http://www.originalsources.com/Document.aspx?DocID=TCKPFQAWF2SBLKI.