David Collier, John Gerring, editor
Routledge, 2009
Buku Teks
Ragin, Charles C., author
University of California Press, 1987
Buku Teks
Williams, Malcolm, 1953-, author
Routledge, 2000
Buku Teks
Blalock, Hubert M., author
Sage Publications, 1982
Buku Teks
Brown, Robert R.
Aldine Pub. Co., 1963
Buku Teks