Παραπομπή σε μορφή APA (7η εκδ.)

Gray, R., & Birmingham, D. (1970). Pre-colonial african trade: Essays on trade in central and eastern Africa before 1900. Oxford University Press.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Gray, Richard, και David Birmingham. Pre-colonial African Trade: Essays on Trade in Central and Eastern Africa Before 1900. London: Oxford University Press, 1970.

Παραπομπή σε μορφή MLA (9th εκδ.)

Gray, Richard, και David Birmingham. Pre-colonial African Trade: Essays on Trade in Central and Eastern Africa Before 1900. Oxford University Press, 1970.