Gaya APA

Portney, , P, , , R., Haas, , R, , B. (1981). Current issues in natural resource policy . Washington D.C.: Rasource for the Future, Inc..

Gaya MLA

Portney, , Paul, , , R., Haas, , Ruth, , B.. "Current issues in natural resource policy". Washington D.C.: Rasource for the Future, Inc., 1981. Text.