Randall, Clarence B.
Gramedia Widiasarana Indonesia, 1998
Buku Teks
Randall, Clarence B.
Washington, D.C. New American Library 1961,
Buku Teks
Pacifico, Carl R.
John Wiley , 1981
Buku Teks
McFarland, Dalton E.
Collier Macmillan, 1974
Buku Teks
Barney, Jay B.
Houghton Miffiln, 1992
Buku Teks