Guernsey, J. L., & Doerr, A. H. (1964). Physical geography. New York: Barron's Educational Series.
Παραπομπή Chicago StyleGuernsey, J. Lee, and Arthur H. Doerr. Physical Geography. New York: Barron's Educational Series, 1964.
Παραπομπή MLAGuernsey, J. Lee, and Arthur H. Doerr. Physical Geography. New York: Barron's Educational Series, 1964.
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