Moran, Theodore H.
Resources for the Future, 1978
Buku Teks
Lowi, Theodore J.
Basic books, 1971
Buku Teks
Beer, Samuel H.
Faber and Faber, 1971
Buku Teks
Epstein, A.L.
Australian Univ. Press, 1971
Buku Teks
Moran, Margaret C.
Peterson's, 2007
Buku Teks