Artikel Jurnal
McDonald, Malcolm HB.
Pertja Jakarta, 1986
Buku Teks
Muhammad Jamaluddin El-Fandy
Bumi Aksara , 1995
Buku Teks
Lovelock, Christopher H., author
Pearson Prentice Hall, 2001
Buku Teks
Lovelock, Christopher H., author
Prentice-Hall, 2000
Buku Teks