Petersen, Andrew, author
Andrew Petersen, 1996
Buku Referensi
Hoag, John D., author
George Braziller, 1963
Buku Teks
Knapp, Stephen, author
Rockport Publishers, 1998
Buku Teks
Blunt, Anthony
[T.t.] Penguin Books [1957]
Buku Teks
Redstone, Louis G.
McGraw-Hill, 1968
Buku Teks