How about this one, although it covers the context of the times…. https://www.amazon.ca/Colossus-Bletchley-Parks-Greatest-Secret/dp/1843543311/ref=asc_df_184354

How about this one, although it covers the context of the times…. https://www.amazon.ca/Colossus-Bletchley-Parks-Greatest-Secret/dp/1843543311/ref=asc_df_1843543311?mcid=74d98c6801133151b152a7b14f879057&tag=googleshopc0c-20&linkCode=df0&hvadid=706833952781&hvpos=&hvnetw=g&hvrand=4765713133088028103&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9000687&hvtargid=pla-587014414474&psc=1&hvocijid=4765713133088028103-1843543311-&hvexpln=0&gad_source=1 https://www.amazon.ca/Colossus-Bletchley-Parks-Greatest-Secr...