Carter, Gwendolen M.
Harcourt, Brace & World, 1962
Buku Teks
Buck, Philip W.
Henry Holt, 1950
Buku Teks SO
edited by Herbert J. Ellison
Westview Press, 1987
Buku Teks SO
Scalapino, Robert A.
University of California Press, 1975
Buku Teks SO
Scalapino, Robert A.
American Enterprise Institute for Public Police, 1972
Buku Teks SO