Natkiel, Richard
Facts on Eile, 1986
Buku Referensi
Easthope, Antony, editor
Routledge , 1991
Buku Teks
Fortinash, Katherine M., author
Mosby, 2003
Buku Teks
Ackley, Katherine Anne
Jovanovich College publishers, 1992
Buku Teks
Albert, Katherine A.
Simon & Schuster , 1996
Buku Teks