Schrag, Clarence C., author
Harper & Row, 1963
Buku Teks
Ogburn, William F., author
Houghton Miffiln, 1958
Buku Teks
Zanden, James W. Vander, author
John Wiley and Sons, 1979
Buku Teks
Ogburn, William F., author
Houghton Mifflin, 1946
Buku Teks
Brikerhaff, David B
West Publishing, 1988
Buku Teks