Carter, Gwendolen M., author
Frederick A. Praeger, 1961
Buku Teks
Bohannan, Paul, author
The National History Press, 1964
Buku Teks
Duffy, James
HArvard University Press, 1961
Buku Teks
Carter, Gwendalen M
Harcourt, Brace ,
Buku Teks
Gunther, John, 1901-1970, author
Hamish Hamilon, 1955
Buku Teks