edited by Gary Hoover, Alta Campbell, Patrick Spain
The Reference Press, 1991
Buku Referensi
Radin, Max
St Paul Minn, 1936
Buku Teks
Guthrie, L.O.
Macmillan, 1956
Buku Teks SO
Whitford, Harold C.
Regents Publishing, 1973
Buku Teks SO
Hombs, Mary Ellen
ABC-Clio, 1990
Buku Teks