Gaya APA
Field, B, C., Field, M, K. (2002).
Environmental economics an introduction. Third Edition (Ed.ke-3).
New York:
McGraw-Hill.
Gaya MLA
Field, Barry, C.., Field, Martha, K..
"Environmental economics an introduction. Third Edition".
Ed.ke-3
New York:
McGraw-Hill,
2002.
Textbook.