APA (7th ed.) Citation

Firmin, S. (1953). Men in the shadows: The story of Scotland Yard's secret agents. Hutchinson.

Chicago Style (17th ed.) Citation

Firmin, Stanley. Men in the Shadows: The Story of Scotland Yard's Secret Agents. London: Hutchinson, 1953.

MLA (8th ed.) Citation

Firmin, Stanley. Men in the Shadows: The Story of Scotland Yard's Secret Agents. Hutchinson, 1953.

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