Healey, Bede
Georgian House, 1972
Buku Teks SO
Muirhead, John Spencer
W. Hodge, 1947
Buku Teks SO
Nicholson, D.F.
F.W. Cheshire, 1955
Buku Teks
Rogers, Margaret
Oceana Publications, 1969
Buku Teks
Finn, Paul
Oxford University Press, 1987
Buku Referensi