Parsons, Glenn, author
Polity Press, 2016
Buku Teks
Abercrombie, Stanley, author
Harper & Row, 1990
Buku Teks
Harrisberger, Lee
Calif., Brooks/Cole Pub. Co., 1966
Buku Teks
Kroes, Peter
Springer, 2012
eBooks
edited by John K. Ryan
The Catholic University of America Press, 1963
Buku Teks