Improved apparatus for deciphering cipher messages
GB177518A
Improvements in apparatus for the enciphering of code expressions, represented by groups of figures, into pronounceable groups of letters, and for the deciphering of thelatter
GB197763A
Improvements in or relating to apparatus for the production of cipher documents especially adapted for telegraphic despatch
GB152625A
Improvements in or relating to the production of cipher documents especially adaptedfor telegraphic despatch
