APA (7th ed.) Citation

Knoop, D. (1931). The riddle of unemployment. Macmillan and co., limited.

Chicago Style (17th ed.) Citation

Knoop, Douglas. The Riddle of Unemployment. London: Macmillan and co., limited, 1931.

MLA (9th ed.) Citation

Knoop, Douglas. The Riddle of Unemployment. Macmillan and co., limited, 1931.