Cooper, Dona, author
Prentice-Hall, 1994
Buku Teks
Lerner, Marcia, author
Random House, 2001
Buku Teks
Cooper, Pat, author
Focal Press, 2005
Buku Teks
Cooper, Louis Blom
Bodley Head, 1961
Buku Teks
Quinlan, David, author
Mandarin, 1994
Buku Referensi