Judd, Charles M., author
Methuen, 1991
Buku Teks
Babbie, Earl, author
Wadsworth and Cengage Learning, 2013 (International edition)
Buku Teks
by Louise H. Kidder ... [and others]
Holt, Rinehart and Winston, 1981
Buku Teks
Sjoberg, Gideon
Harper & Row Publishers, 1968
Buku Teks
Weber, Max, 1864-1920, author
Transaction Publishers, 2011
Buku Teks