Artikel Jurnal
Brown, Lester R.
Overseas Development Council , 1974
Buku Teks
Barnett, Harold J., author
John Hopkins Press, 1963
Buku Teks
The University of Massachusetts Pres, 1981
Buku Teks
Akhmad Fauzi, author
Gramedia Pustaka Utama, 2010
Buku Teks