Gaya APA
Gudorf, C, E, &, H, J, E. (2010).
Boundaries: A casebook in environmental ethics, 2nd ed. .
Washington:
Washington DC.
Gaya MLA
Gudorf, Christine, E., &, Huchingson,, James, E..
"Boundaries: A casebook in environmental ethics, 2nd ed. ".
Washington:
Washington DC,
2010.
Buku.