American Enterprise Institute for Public Policy Research, 1979
Buku Teks
Blackwell , 2001
eBooks
Blackwell, 2003
eBooks
edited by Jonathan Kelley and Clive Bean
George Allen & Unwin, 1988
Buku Teks
McDougal, Myres S. (Myres Smith), 1906-1998, author
Yale University Press, 1967
Buku Teks