Cornman, James W., author
Macmillan, 1968
Buku Teks
Hospers, John, author
Roudledge, 1988
Buku Teks
Stumpf, Samuel Enoch, 1918-1998, author
McGraw-Hill, 1971
Buku Teks
Taylor, Paul C., author
Polity Press, 2013
Buku Teks
Angle, Stephen C., author
Polity Press, 2017
Buku Teks