IMO, an unattributed quote (or attributed to "unknown", or you know, doing slightly more research than "the quickest reference you can find") is better than putting a known-wrong reference.

Hi Neil. The attribution is correctly given here: https://martinfowler.com/bliki/TwoHardThings.html

(Hint... it's me.)

Wrong information is worse than no information. If the source is not known or if you don't want to spend the time to find it, just say "unknown" or "as someone said"