Deutsch, Babette
Funk & Wagnalls, 1957
Buku Referensi
Drury, John
Story Press, 1995
Buku Referensi
Hewitt, A.H.
Scientific Publications, 1965
Buku Teks
Lennard, John
University Press, 2005
Buku Referensi
Cuddon, J.A.
Penguin Books, 1979
Buku Referensi