London Collier-Macmillan 1965,
Buku Teks
Sambrook, G.A.
Longmans, Green, 1947
Buku Teks
editor, Tom McArthur ; managing editor, Feri McArthur
Oxford University Press, 1992
Buku Referensi
edited by Henry Cecil
George Routledge & Sons, 1946
Buku Referensi
Burton, Samuel Holroyd
Macmillan, 1992
Buku Teks