Παραπομπή APA

Powell, T. (2001). The principles of transport economics. London: PTRC Education and Research Services Ltd..

Παραπομπή Chicago Style

Powell, Tim. The Principles of Transport Economics. London: PTRC Education and Research Services Ltd., 2001.

Παραπομπή MLA

Powell, Tim. The Principles of Transport Economics. London: PTRC Education and Research Services Ltd., 2001.

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