Hughes, D. (1992). Environmental Law (2nd ed.). Butterworths.
Chicago Style aipamenaHughes, David. Environmental Law. 2nd ed. London: Butterworths, 1992.
MLA aipamenaHughes, David. Environmental Law. 2nd ed. Butterworths, 1992.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.