Strahler, Arthur N.
Elements of physical geography
John Wiley & Sons, 1976
 Buku Teks
Strahler, Arthur N.
Elements of physical geography
John Wiley & Sons, 1989
 Buku Teks
Strahler, Arthur N.
Physical geography
John Wiley & Sons, 1975
 Buku Teks
Trewartha, Glenn T.
Elements of geography : physical and cultural
McGraw-Hill, 1967
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Fundamentals of physical geography
oleh Glenn T. Trewartha [and others]
McGraw-Hill, 1977
 Buku Teks