Collier-MacMillan International, 1969
Buku Teks
Maclagan, Thomas T., author
Thomas Nelson and Son, 1929
Buku Referensi
Bauer, Laurie
Combridge University Press, 1983
Buku Teks
French, F. G., author
Oxford University Press, 1947
Buku Teks
Fitikides, T.J.
longmans, group limited, 1964
Buku Teks