Kull, Irving S.
Rutgers University, 1952
Buku Teks
editor, Gorton Carruth
Thomas Y. Growell, 1962
Buku Referensi
edited by Richard B. Morris
Harper and Row , 1965
Buku Referensi
ECAM Publications, 1989
Buku Teks
Hudson, Robert V., author
Garland publishing, 1987
Buku Referensi