Holmes, Richard, author
Harper Collins , 2001
Buku Teks
Karl, Frederick R., author
Farrar, Straus and Giroux, 1964
Buku Teks
Bryn Mawr : Intercellegiate Studies Institute
Majalah, Jurnal, Buletin
Smith, Leslie, author
Macmillan, 1989
Buku Teks
Harcourt, Brace and company, 1950
Buku Teks