I am by now perfectly aware that "Bletchley Park had much more available to them than 'Bombes,'" but I'm finding it difficult to find on-line explanations of their many other types of "rapid analytic machinery" which are not shielded by "paywalls." No, I really am not interested in paying $75.00 (USD) for access to a single article. Therefore, what books and/or article sources might you recommend?
Removing barriers in the way of science
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