Gray, O. S. (1977). Cases and materials on environmental law - supplement 1977 (2nd ed.). The Bureau of National Affairs.
Chicago Style aipamenaGray, Oscar S. Cases and Materials on Environmental Law - Supplement 1977. 2nd ed. Washington DC: The Bureau of National Affairs, 1977.
MLA aipamenaGray, Oscar S. Cases and Materials on Environmental Law - Supplement 1977. 2nd ed. The Bureau of National Affairs, 1977.
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