Walton, Donald
McGraw-Hill , 1989
Buku Teks SO
Cleary, Jon
Collins Publishers Australia, 1947
Buku Teks SO
Helmut Anheier, Yudhishthir Raj Isar, editor
SAGE Publications, 2008
Buku Teks SO
Novak, Brenda
PT Gramedia Pustaka Utama, 2018
Buku Teks SO
Vernon, Philip E.
Methuen, 1972
Buku Teks SO