APA (7th ed.) Citation

Yorke, F. R. S., & Penn, C. (1939). A key to modern architecture. Blackie and Son limited.

Chicago Style (17th ed.) Citation

Yorke, Francis Reginald Stevens, and Colin Penn. A Key to Modern Architecture. London ; Glasgow: Blackie and Son limited, 1939.

MLA (9th ed.) Citation

Yorke, Francis Reginald Stevens, and Colin Penn. A Key to Modern Architecture. Blackie and Son limited, 1939.