Παραπομπή APA

(1963). Calibrating and testing a gravity model with a small computer. Washington, DC: Government Printing Office.

Παραπομπή Chicago Style

Calibrating and Testing a Gravity Model With a Small Computer. Washington, DC: Government Printing Office, 1963.

Παραπομπή MLA

Calibrating and Testing a Gravity Model With a Small Computer. Washington, DC: Government Printing Office, 1963.

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