Gellhorn, Ernest, author
West , 1994
Buku Teks
Dobbyn, John F., author
West Publishing, 1989
Buku Teks
Lowe, John S., author
West Publishing, 1995
Buku Teks
Loewy, Arnold H.
St.paul Minn, 1987
Buku Teks
Gellhorn, Ernest, author
West Publishing Company, 1972
Buku Teks