Carter, Gwendolen M., author
Frederick A. Praeger, 1961
Buku Teks
Mires, Charlene
University of Pennsylvania Press, 2002
Buku Teks
Furnivall, JS
Solidaridad publishing house, 1974
Buku Teks
University of Zagreb, 1991
Buku Teks
Dahm, Bernhard, author
Cornell University Press, 1969
Buku Teks