ROYEN, W. V., & BENGTSON, N. A. (1964). Fundamentals of economic geography: An introduction tothe study of resources. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)ROYEN, William Van, agus Nels A. BENGTSON. Fundamentals of Economic Geography: An Introduction Tothe Study of Resources. Englewood Cliffs: Prentice-Hall, 1964.
Lua MLA (9ú heag.)ROYEN, William Van, agus Nels A. BENGTSON. Fundamentals of Economic Geography: An Introduction Tothe Study of Resources. Prentice-Hall, 1964.
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