Rogers, Peter
FA. Davis, 1977
Buku Teks
Burnard, Philip, author
Chapman&Hall,, 1995
Buku Referensi
Colbert, Don, author
Siloam A Strang Company, 2007
Buku Teks
New York : Macmillan, 1993,
Buku Referensi
Potter, Patricia A., author
Mosby , 1998
Buku Teks