Thoman, R. S. (1974). The geography of economic activity (3rd ed.). McGraw-Hill.
Cita Chicago (17th ed.)Thoman, Richard S. The Geography of Economic Activity. 3rd ed. New York: McGraw-Hill, 1974.
Cita MLA (9th ed.)Thoman, Richard S. The Geography of Economic Activity. 3rd ed. McGraw-Hill, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.