Epstein, Edwin M., author
Prentice-Hall, 1969
Buku Teks
Krooss, Herman Edward, 1912-1975, author
Prentice-Hall, 1972
Buku Teks
Alden, John Richard, author
Harper & Row Publishers, 1963
Buku Teks
Bartholomew, Paul C., author
W.M.C. Brown, 1951
Buku Teks
Wilson, James Q., author
D.C. Heath, 1995
Buku Teks