The breaking of the Lorenz Cipher: An introduction to the theory behind the operational role of "colossus" at BP

Carter, F. L. (1997). The breaking of the Lorenz Cipher: An introduction to the theory behind the operational role of “colossus” at BP. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) (Vol. 1355, pp. 74–88). Springer Verlag. https://doi.org/10.1007/bfb0024451