Gray, O. S. (1973). Cases and materials on environmental law (2nd ed.). The Bureau of National Affairs.
Dyfyniad Arddull ChicagoGray, Oscar S. Cases and Materials on Environmental Law. 2nd ed. Washington: The Bureau of National Affairs, 1973.
Dyfyniad MLAGray, Oscar S. Cases and Materials on Environmental Law. 2nd ed. The Bureau of National Affairs, 1973.
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