Inkeles, Alex, author
Harvard University Press, 1974
Buku Teks
Huyghe, Rene, author
Weatherhill, 2007
Buku Teks
Krutch, Joseph Wood, author
Greenwood Press, 1979
Buku Teks SO
Toynbee, Arnold J., author
Kodansha International, 1976
Buku Teks
Chambers, Iain, author
Routledge, 2001
Buku Teks