by Collin J. Watson [and others]
Allyn and Bacon, 1993
Buku Teks
Daniel, Wayne W., author
Houghton Miffiln, 1989
Buku Teks
Allen, R.G.D., author
Hutchinson University Library, 1972
Buku Teks
Mendenhall, William, author
Cal Duxbury Press , 1971
Buku Teks
Allyn and Bacon, 1993
Buku Teks