Sirait, Ramosta S., author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2009
UI - Skripsi (Open)
Crawford, Adam
Longman, 1998
Buku Teks
DeLeon-Granados, William, author
Northeastern University Press, 2000
Buku Teks
Brandon C. Welsh, David P. Farrington.
Springer, 2006
Buku Teks
Crawford, Adam
Longman, 1998
Buku Teks