Posin, Daniel Q.
St. Paul Minnesota, 1993
Buku Teks
Kidner, Richard
Blackstone, 1998
Buku Teks
Thomas, Meryl, author
Blackstone Press LTD, 2000
Buku Teks
Nightingale, Kath, author
Prentice-Hall, 2002
Buku Teks
edited by Emile Woolf
Pitman, 1986
Buku Teks