Carlton, Katherine Tasheff
Gloucester, Ma Rockport Publisher 2001,
Buku Referensi
Ploeger, Katherine M.
NTC Publishing Group, 2000
Buku Teks
Mansfield, Katherine, author
Golden Press, 1978
Buku Teks
Begon, Michael, author
University Park Oress, 1979
Buku Teks
Dangaroo Press, 1989
Buku Teks