Wolf, Charles
Princeton University press, 1960
Buku Teks
Isaacs, Harold R.
Macmillan, 1947
Buku Teks
Langie, G.S.S.J. Ratu, author
Pustaka Sinar Harapan, 1982
Buku Teks
Wolf, Charles
Princeton University Press , 1960
Buku Teks
Luhulima, C.P.F., author
Pustaka Pelajar, 2011
Buku Teks