Snyder, Thomas Elliott, author
Smithsonian Institution, 1956
Buku Teks
Kemp, Herman C., author
KITLV Press, 1990
Buku Referensi
Clamp, Cynthia G. L., author
Sage, 1999
Buku Teks
Bridson, Gavin D.R., author
Gerland Publishing, 1994
Buku Teks
Freedman, Ronald, author
Irvington, 1975
Buku Teks