Carter, Gwendolen M.
Frederick A. Praeger, 1961
Buku Teks
Mires, Charlene
University of Pennsylvania Press, 2002
Buku Teks
Mass., A. J. St. Onge, 1970
Buku Teks
Furnivall, JS
Solidaridad publishing house, 1974
Buku Teks
University of Zagreb, 1991
Buku Teks