Gaya APA

Ingpen, R., Wilkinson, P. (1991). Encyclopedia of World Events: Eighty turning points in history . DY, Great Britain: Dragon\'s World Ltd.

Gaya MLA

Ingpen, Robert., Wilkinson, Philip. "Encyclopedia of World Events: Eighty turning points in history". DY, Great Britain: Dragon\'s World Ltd, 1991. Referensi.