Longwell, C. R., Flint, R. F., & Sanders, J. E. (1969). Physical geology. Wiley.
Lua i Stíl Chicago (17ú heag.)Longwell, Chester R., Richard Foster Flint, agus John E. Sanders. Physical Geology. New York: Wiley, 1969.
Lua MLA (9ú heag.)Longwell, Chester R., et al. Physical Geology. Wiley, 1969.
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