Laski, Harold J., author
Manchester University Press, 1951
Buku Teks
Yerby, George., author
Routledge, 2016
Buku Teks
[Universitas Indonesia, ], 2004
UI - Skripsi (Membership)
Ayu Novita Pramesti, author
Universitas Indonesia, 2011
UI - Skripsi (Open)
Universitas Indonesia, 2003
UI - Skripsi (Membership)