Look at the research of Linda Moulton Howe. I watched an episode of "Ancient Aliens"–which I normally watched for entertainment. It was one on the Majestic 12. She had all kinds of government documentation outlining Eisenhower, MJ-12, and the beginning of the US military reverse-engineering alien tech. She also had a manifest of "non-terrestrial" officers on Navy ships as I recall. She practices real journalism with multiple sources…something you don't see much of any more. Check her out. Here's that episode, but she writes and has many other credible folks that she has interviewed t http://www.ascensionwithearth.com/2017/09/ancient-aliens-majestic-twelve-linda.html
Probably others out there as well.