edited by Alvin Sullivan
Greenwood Press, 1986
Buku Referensi
Mentor book, 1956
Buku Referensi
Hart, James D., author
Oxford University Press, 1986
Buku Referensi
Frank, Marcella, author
Prentice-Hall, 1972
Buku Teks
Christ, Henry
Lexington, 1982
Buku Teks