I used to work in a really niche engineering field. The amount of stuff I used from documents released by the US military was non-trivial. Never anything direct

I used to work in a really niche engineering field. The amount of stuff I used from documents released by the US military was non-trivial. Never anything directly, but most of the time the docs were useful enough to shed deeper light and context on the trade publications and standards I was using when the history and intent behind a lot of calculations wasn't clear.