Westview Press, 1992
Buku Teks
edited by Richard Tardanico
Sage, 1987
Buku Teks
edited by Louis W. Goodman, William M. LeoGrande, Johanna Mendelson Forman
Westview Press, 1992
Buku Teks
Scott, Andrew M., author
Holt, Rinehart & Winston, 1959
Buku Teks
Rodriguez, Mario
Prentice-Hall, 1965
Buku Teks