Παραπομπή APA

Polak, F. L., & Boulding, E. The image of the future: Enlightening the past, orientating the present, forecasting the future. Leyden : new York: A. W. Sythoff Oceana Publications.

Παραπομπή Chicago Style

Polak, Frederick Lodewijk, and Elise Boulding. The Image of the Future: Enlightening the Past, Orientating the Present, Forecasting the Future. Leyden : new York: A. W. Sythoff Oceana Publications.

Παραπομπή MLA

Polak, Frederick Lodewijk, and Elise Boulding. The Image of the Future: Enlightening the Past, Orientating the Present, Forecasting the Future. Leyden : new York: A. W. Sythoff Oceana Publications.

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