Weston, Marie-Therese
NTC Publishing Group, 1994
Buku Teks
Robertson, Silvia
Hodder & Stoughton, 1994
Buku Teks
Coggle, Paul, author
NTC Publishing Group, 1994
Buku Teks
Weston, Burns H.
Syracuse University Press, 1971
Buku Teks
Weston, Martin
Berg Publishers, 1993
Buku Teks