Hyman, Anthony
Oxford University Press, 1982
Buku Teks SO
Ibbot, Anthony Charles
Calif Anthony Charles Ibbot Foundation , 1993
Buku Teks
McMillan, 1962
Buku Referensi
Deem, Bill R.
Reston Publishing, 1980
Buku Teks
American Geogphysical Union, 1966
Buku Teks