APA (7 वां संस्करण) प्रशस्ति पत्र
Alpers, E. A. (1975). Ivory & Slaves in East central Africa: Changing patterns of international trade to the later nineteenth century. Heinemann.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र
Alpers, Edward A. Ivory & Slaves in East Central Africa: Changing Patterns of International Trade to the Later Nineteenth Century. London: Heinemann, 1975.
एमएलए (9वां संस्करण) प्रशस्ति पत्र
Alpers, Edward A. Ivory & Slaves in East Central Africa: Changing Patterns of International Trade to the Later Nineteenth Century. Heinemann, 1975.
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