edited by Howard J. Wiarda, Harvey F. Kline
Westview Press, 2007
Buku Teks
Mann, Arthur
Gadjah Mada University Press, 1990
Buku Teks
Busey, James L., author
Random House, 1968
Buku Teks
edited by Juan J. Linz and Alfred Stepan
John Hopkins University Press, 1978
Buku Teks
Clagett, Helen L.
Oceana Publications, 1952
Buku Teks