“The National Cryptologic Museum, located adjacent to the National Security Agency at Ft. George G. Meade, Maryland, has a reference library containing a collection of unclassified and declassified books and documents relating to every aspect of cryptology. The Museum Library has helpfully published its catalogue online upon request: CryptoLibraryCatalogue
The home page for the National Cryptologic Museum is here: https://www.nsa.gov/about/cryptologic-heritage/museum/“