Kagan, D., & Ozment, S. E. (1987). The Western heritage (3rd .ed.). Macmillan.

Kagan, Donald, and Steven E. Ozment. The Western Heritage. 3rd .ed. New York: Macmillan, 1987.

Kagan, Donald, and Steven E. Ozment. The Western Heritage. 3rd .ed. Macmillan, 1987.