Buku Teks
Robertson, Priscilla
University Press, 1971
Buku Teks SO
Link, Robert G.
Columbia University Press, 1959
Buku Teks
edited by Jack A. Goldstone, Ted Robert Gurr, Farrokh Moshiri
Westview Press, 1991
Buku Teks SO
Kuhn, Thomas S.
University of Chicago Press, [c1970]
Buku Teks SO