Angel, Juvenal L.
World Trade Academy Press , 1971
Buku Teks
Shrader, Robert L.
McGraw-Hill, 1977
Buku Teks
Priestley, J. B. (John Boynton), 1894-1984, author
J.M. Dent and Sons, 1953
Buku Teks
Bobrick, Benson
Penguin Books, 1997
Buku Teks
Carr, Caleb, author
Random House, 1997
Buku Teks