APA (7th ed.) Citation

Hewat, T., & Waterton, W. A. (1955). The Comet riddle. F. Muller.

Chicago Style (17th ed.) Citation

Hewat, Tim, and W. A. Waterton. The Comet Riddle. [London]: F. Muller, 1955.

MLA (9th ed.) Citation

Hewat, Tim, and W. A. Waterton. The Comet Riddle. F. Muller, 1955.