Artikel Jurnal
edited by Goerge Thomas Kurian, Graham T.T. Molitor
Macmillan Library Reference USA, 1996
Buku Referensi
translated, described, and annotated by A.C. Scott
Caves Book, 1984
Buku Teks SO
Kartomi, Margaret J.
University of Chicago Press, 1990
Buku Teks SO
Hildebrand, David K., 1940-
John Wiley & Sons, 1977
Buku Teks SO