James P Sterba
Routledge, 2001
Buku Teks
Macridis, Roy C., author
Little, Brown, 1983
Buku Teks
Koopmans, Tim, author
Cambridge University Press, 2003
Buku Teks
Field, G. Lowell, author
Cornell University Press, 1967
Buku Teks
Fowler, Robert Booth, author
University Press of Kansas, 1991
Buku Teks