Gaya APA
Davis, M, L., Cornwell, D, A. (1991).
Introduction To Environmental Engineering (Second Ed.).
Singapore:
Mcgraw - Hill International Ed.
Gaya MLA
Davis, Mackenzie, L.., Cornwell, David, A..
"Introduction To Environmental Engineering".
Second Ed.
Singapore:
Mcgraw - Hill International Ed,
1991.
Text.