Frode Weierud: Bletchley Park’s Sturgeon, the Fish that Laid No Eggs. In: Rutherford Journal (englisch), S. 4, PDF; 810 kB, abgerufen am 30. August 2021.
Donald W. Davies: The early models of the Siemens and Halske T52 cipher machine. In: Cryptologia 1983, 7:3, S. 241, doi:10.1080/0161-118391857964.
Donald W. Davies: New Information on the history of the Siemens and Halske T52 cipher machines. In: Cryptologia 1994, 18:2, S. 145, doi:10.1080/0161-119491882801.
Donald W. Davies: The early models of the Siemens and Halske T52 cipher machine. In: Cryptologia 1983, 7:3, S. 241, doi:10.1080/0161-118391857964.
Donald W. Davies: New Information on the history of the Siemens and Halske T52 cipher machines. In: Cryptologia 1994, 18:2, S. 145, doi:10.1080/0161-119491882801.
Frode Weierud und Sandy Zabell: German mathematicians and cryptology in WWII. Cryptologia, doi:10.1080/01611194.2019.1600076, S. 119.
ticomarchive.com
TICOM/I-78: Interrogation of Oberstlt. Mettig on the History and Achievements of OKH/AHA/In 7/VI. S. 11–12, ticomarchive.com.