Schawartz, Bernard
At The University Press, 1955
Buku Teks
Mason, Alpheus Thomas,1899-1989
Prentice-Hall, 1993
Buku Teks
Strong, Frank R.
Dennis & Co., 1950
Buku Teks
Fisher, Louis
McGraw-Hill, 1988
Buku Teks
Pritchett, C. Herman
McGraw-Hill, 1963
Buku Teks