Majul, Cesar A., author
LP3ES, 1989
Buku Teks
Nadeak, Kustigar, author
Pustaka Sianar Harapan, 1986
Buku Teks
Saikal, Amin
Westview Press, 1991
Buku Teks
Dixit, J.N. (Jyotindra Nath)
Konark Publishers, 2000
Buku Teks
Scott, Franklin D.
University of Minnesota Press, 1977
Buku Teks