Authors. (2008). Worlds Together, Worlds Apart: A History of the World from the Beginnings of Humankind to the Present - (Vol. 1): Beginning through the fifteenth century (Tái bản lần thứ 2.). New York: W. W. Norton & Company.

Authors. Worlds Together, Worlds Apart: A History of the World From the Beginnings of Humankind to the Present - (Vol. 1): Beginning Through the Fifteenth Century. Tái bản lần thứ 2. New York: W. W. Norton & Company, 2008.

Authors. Worlds Together, Worlds Apart: A History of the World From the Beginnings of Humankind to the Present - (Vol. 1): Beginning Through the Fifteenth Century. Tái bản lần thứ 2. New York: W. W. Norton & Company, 2008.