Allen, J. M. (1997). Study guide for Ralph, Lerner, Meacham, Wood, Hull, and Burns "World civilizations" (9th ed.). New York ; London: W. W. Norton.
Citación estilo ChicagoAllen, J. Michael. Study Guide for Ralph, Lerner, Meacham, Wood, Hull, and Burns "World Civilizations". 9th ed. New York ; London: W. W. Norton, 1997.
Cita MLAAllen, J. Michael. Study Guide for Ralph, Lerner, Meacham, Wood, Hull, and Burns "World Civilizations". 9th ed. New York ; London: W. W. Norton, 1997.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.