Downs, Anthony, author
Harper and Row, 1975
Buku Teks
Acemoglu, Daron, author
Cambridge University Press, 2006
Buku Teks
MacIver, Robert M., author
Alfred A. Knopf, 1952
Buku Teks
Rosen, George, author
University California Press, 1966
Buku Teks
Hart, George Henry Charles, 1893-, author
The Netherlands Information Bureau, 1942
Buku Teks