Gaya APA
FIELD, B, C., FIELD, M, K. (2006).
ENVIRONMENTAL ECONOMICS: AN INTRODUCTION SEVENTH EDITION (SEVENTH EDITION).
NEW YORK:
MC GRAW HILL EDUCATION.
Gaya MLA
FIELD, BARRY, C., FIELD, MARTHA, K.
"ENVIRONMENTAL ECONOMICS: AN INTRODUCTION SEVENTH EDITION".
SEVENTH EDITION
NEW YORK:
MC GRAW HILL EDUCATION,
2006.
Text.