APA (7th ed.) Citation

Wallis, J. H. (1962). The challenge of middle age / by J.H. Wallis. Routledge and Kegan Paul.

Chicago Style (17th ed.) Citation

Wallis, J. H. The Challenge of Middle Age / by J.H. Wallis. Routledge and Kegan Paul, 1962.

MLA (9th ed.) Citation

Wallis, J. H. The Challenge of Middle Age / by J.H. Wallis. Routledge and Kegan Paul, 1962.

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