Lewis, Sharon Mantik, author
Mosby, 1996
Buku Teks
Chabay, Ruth W, author
John Wiley & Sons, 2007
Buku Teks
Wuncsh, K.H.
"Berlin :VEB Deutscher Verlag ,1973",
Buku Teks
Gray, Harry B.
"Berlin: Walter de Gruyter, 1973",
Buku Teks
Crelyn, R.J.
"Chichester: John Wiley & Sons, 1990",
Buku Teks