"Bonatz, Heinz". Deutsche Nationalbibliothek – Katalog der Deutschen Nationalbibliothek. Retrieved 13 October 2016.
doi.org
Erskine, Ralph (1992). "The German Naval Grid in World War II". Cryptologia. 16 (1): 39–51. doi:10.1080/0161-119291866757.
Ratcliff, R. A. (1999). "Searching for security: The German investigations into Enigma's security". Intelligence and National Security. 14 (1): 146–167. doi:10.1080/02684529908432527.
Erskine, Ralph (2 January 2008). "Naval Enigma: The breaking of Heimische and Triton". Intelligence and National Security. Journal: Intelligence and National Security, Volume:3, Date:1988, Issue: 1. 3: 162–183. doi:10.1080/02684528808431933.
Erskine, Ralph (1996). "Naval enigma: An astonishing blunder". Intelligence and National Security. 11 (3): 468–473. doi:10.1080/02684529608432372.
Friedman, William. "Chapter IV"(PDF). ABSTRACTS FROM "GERMAN NAVAL COMMUNICATIONS INTELLIGENCE". Folder 152; Document ref:A66767. Vol. IF-210 Copy #3. William F. Friedman Collection of Official Papers. pp. 135–161. Retrieved 16 September 2016 – via nsa.gov.
ticomarchive.com
Rezabek, Randy. "B-Dienst (Navy)". TICOM Archive Secret Intelligence in Nazi Germany. TICOM. Archived from the original on 16 January 2019. Retrieved 27 April 2016.
Rezabek, Randy. "B-Dienst (Navy)". TICOM Archive Secret Intelligence in Nazi Germany. TICOM. Archived from the original on 16 January 2019. Retrieved 27 April 2016.
"B-Dienst (Navy)". www.ticomarchive.com. TICOM Archive. Archived from the original on 16 January 2019. Retrieved 15 June 2015.