Cita APA (7th ed.)

Gregor, H. F. (1963). Environment and economic life; an economic and social geography. Van Nostrand.

Cita Chicago (17th ed.)

Gregor, Howard F. Environment and Economic Life; an Economic and Social Geography. Princeton, N. J: Van Nostrand, 1963.

Cita MLA (9th ed.)

Gregor, Howard F. Environment and Economic Life; an Economic and Social Geography. Van Nostrand, 1963.