Seligmann, Matthew S. Naval Intelligence from Germany: The Reports of the British Naval Attachés in Berlin, 1906-1914 (Navy Records Society, Vol. 152). Aldershot, Hants, and Burlington, Vt.: Ashgate for Navy Records Society, .

The full index for this resource is available at the Navy Records Society website: https://www.navyrecords.org.uk/the-defeat-of-the-enemy-attack-on-shipping-1939-1945/ The full text is available with NRS membership.