Blodgett, Ralp H., author
Macmillan, 1949
Buku Teks
Gregory, Paul R., author
Hougton Mifflin, 1985
Buku Teks
Angresano, James, author
Prentice-Hall, 1992
Buku Teks
edited by Morris Bornstein
Richard D. Irwins, 1969
Buku Teks
Chilcote, Ronald H., author
Routledge, 2000
eBooks
Halm, George N.
Feffer and Simons, 1971
Buku Teks