APA (7th ed.) Citation

Palmer, W. T., & Muirhead, L. R. (1939). Penguin guide to the Lake District. Penguin.

Chicago Style (17th ed.) Citation

Palmer, W. T., and L. Russell Muirhead. Penguin Guide to the Lake District. London: Penguin, 1939.

MLA (9th ed.) Citation

Palmer, W. T., and L. Russell Muirhead. Penguin Guide to the Lake District. Penguin, 1939.

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