Devins, Delbert W.
John Wiley & Sons, 1982
Buku Teks
Ridley, B.K., author
John Wiley & Sons, 1979
Buku Teks
De Blij, Harm J., author
John Wiley & Sons, 1993
Buku Teks
De Blij, Harm J., author
John Wiley & Sons, 1996
Buku Referensi
Tillery, Bill W., author
McGraw-Hill, 2012
Buku Teks