edited by Richard A. Easterlin
University of Chicago Press, 1980
Buku Teks
Zelinsky, Wilbur, author
Prentice-Hall, 1966
Buku Teks
Plane, David A., author
John Wiley & Sons, 1994
Buku Teks
Zelinsky, Wilbur
Prentice Hall International, 1970
Buku Teks
Tan, Ngoc Chau
Unesco, 1972
Buku Teks