1. Cassell’s English Dictionary Including Words and Phrases Current among the English-speaking Peoples of the World, Together with Many Technical and Scientific Terms in Common Use. 1968. 4th ed. Completely revised and enlarged by Arthur L. Hayward and John J. Sparkes. London: Cassell.
2. Chambers Twentieth Century Dictionary. 1972. New edition. ed. A.M. Macdonald. Edinburgh: Chambers.
3. Chambers Twentieth Century Dictionary. 1983. New edition, ed. E.M. Kirkpatrick. Edinburgh: Chambers.