APA (7th ed.) Citation

Liddell, R. S. (1928). The key of content. Cassell.

Chicago Style (17th ed.) Citation

Liddell, R. Scotland. The Key of Content. London: Cassell, 1928.

MLA (8th ed.) Citation

Liddell, R. Scotland. The Key of Content. Cassell, 1928.

Warning: These citations may not always be 100% accurate.