Snyder, Thomas Elliott, author
Smithsonian Institution, 1956
Buku Teks
Kemp, Herman C., author
KITLV Press, 1990
Buku Referensi
Groenendael, Victoria M. Clara van, author
Foris Publications, 1987
Buku Referensi
Freedman, Ronald, author
Irvington, 1975
Buku Teks
Clamp, Cynthia G. L., author
Sage, 1999
Buku Teks