Wallen, R. N. (1992). Introduction to physical geography. WM C. Brown.
Chicagoスタイル(17版)引用形式Wallen, Robert N. Introduction to Physical Geography. Boulevard: WM C. Brown, 1992.
MLA(9版)引用形式Wallen, Robert N. Introduction to Physical Geography. WM C. Brown, 1992.
警告: この引用は必ずしも正確ではありません.