Converse, Paul Dulaney, 1889-
Prentice-Hall, 1947
Buku Teks
Jones, Fred M.
Richard D. Irwin , 1957
Buku Teks
Egan, John, 1952-
Sage Publications, 2015
Buku Teks
Tousley, Rayburn D.
Macmillan , 1962
Buku Teks
Clark, Fred E.
MacMillan Co., 1931
Buku Teks