Sjoberg, Gideon
Harper & Row Publishers, 1968
Buku Teks
Impex India, 1967
Buku Teks
Weber, Max, 1864-1920, author
Transaction Publishers, 2011
Buku Teks
Judd, Charles M., author
Methuen, 1991
Buku Teks
Babbie, Earl, author
Cengage Learning, 2016
Buku Teks