Hanks, Lucien M
Aldine Atherton, 1972
Buku Teks
edited by Jose I. Furtado
Harwood Academic , 1990.
Buku Teks
Odum, Eugene Pleasants
Saunders College, 1983
Buku Teks
Brewer, Richard
Saunders College Publishing, 1994
Buku Teks
Ehrlich, Paul R.
Macmillan, 1987
Buku Teks