Schellenberger, Robert E.
John Wiley & Sons, 1982
Buku Teks
Boseman, Glenn
John Wiley & Sons, 1988
Buku Teks
by Joseph C. Latona ... [and others]
South-Western Publishing, 1984
Buku Teks
Steiner, George A. (George Albert), 1912-, author
Macmillan, 1977
Buku Teks
Buchholz, Regene A.
Prentice-Hall, 1986
Buku Teks