Hardin, Garrett
W.H. Freeman, 1969
Buku Teks
Ness, Gayl D.
The John Hopkins University Press , 1984
Buku Teks
Feliciano, Gloria D., author
UNESCO, 1978
Buku Teks
Peel, John
Churchill Livingstone, 1975
Buku Teks
American Association for the Advancement of Science, 1975
Buku Teks