Howlin, Patricia, author
John Wiley & Sons, 1999
Buku Referensi
Dacey, John S., author
Jossey-Bass Inc, 2000
Buku Teks
Kennedy, David, author
Bay Books, 1988
Buku Referensi
Diana Aprillia, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2012
UI - Tesis (Open)
Knowles, Malcolm S., author
Cambridge University Press, 1980
Buku Teks