edited by P. Ebow Bondzi-Simpson
Praeger, 1992
Buku Teks
Burnell, Peter J.
Westview Press, 1986
Buku Teks
Williams, Marc
Harvester Wheatsheaf , 1994
Buku Teks
Ebenstein, William, author
Prentice-Hall, 1967
Buku Teks
Ebenstein, William, author
Prentice-Hall, 1954
Buku Teks