Kirk-Greene, C. W. E.
Foulsham, 1992
Buku Teks
Moffatt, C.W. Paget
University Tutorial Press, 1`929
Buku Teks
Bean, C.E.W. (Charles Edwin Woodrow)
Angus and Robertson, 1963
Buku Teks
Clason, W. E., 1898-, author
Elsevier Scientific Publishing, 1976
Buku Referensi
Martin, Samuel E.
Tuttle Company, 1956
Buku Teks