APA (7e ed.) Bronvermelding

Singer, K. D. (1943). Duel for the northland: The war of enemy agents in Scandinavia. R. M. McBride & Co.

Chicago (17e ed.) Bronvermelding

Singer, Kurt D. Duel for the Northland: The War of Enemy Agents in Scandinavia. New York: R. M. McBride & Co, 1943.

MLA (9e ed.) Bronvermelding

Singer, Kurt D. Duel for the Northland: The War of Enemy Agents in Scandinavia. R. M. McBride & Co, 1943.