Hotchkiss, George Burton
Alexander Hamilton Institute , 1961
Buku Teks
Wells, William D.
Prentice-Hall, 2000
Buku Teks
Weilbacher, William M
Macmillan, 1979
Buku Teks
Lane, W. Ronald
New York, 2000
Buku Teks
Ahuja, B. N.
Surjeet Publications, 1989
Buku Teks