De Blij, Harm J., author
John Wiley & Sons, 1971
Buku Teks
Fuson, Robert H.
Kendall/Hunt Publishing Co., 1977
Buku Teks
Holt-Jensen, Arild, author
Publications, 2003
Buku Teks
Berry, Joseph K., author
GIS World, 1993
Buku Teks
Taylor and Francis, 2018
Buku Teks