Lapiere, Richard T.
McGraw-Hill, 1946
Buku Teks
Ogburn, William F.
Houghton Mifflin, 1964
Buku Teks
Farley, John E.
Prentice-Hall, 1992
Buku Teks SO
Nobbs, Jack
Macmillan Education, Ltd., 1989
Buku Teks SO
Finsterbusch, Kurt
McGraw-Hill, 2006
Buku Teks SO