Gaya APA
Humphrey, C, R., Buttel, F, R. (1982).
Environment, Energy, and Society .
Belmont California:
Wadsworth Publishing Company.
Gaya MLA
Humphrey, Craig, R.., Buttel, Frederick, R..
"Environment, Energy, and Society".
Belmont California:
Wadsworth Publishing Company,
1982.
Text.