edited by Roscoe C. Martin
Syracuse University Press , 1965
Buku Teks
Linden, Russell Mathew
Jossey-Bass, 1994
Buku Teks
Irish, Marian D.
Prentice-Hall, 1962
Buku Teks SO
Sayre, Wallace S.
Barnes & Noble, 1964
Buku Teks SO
Griffith, Ernest S.
Frederick A. Praeger, 1954
Buku Teks SO