I am especially interested in the link between UFOs and nuclear materials.
Robert Hastings is the lead civil researcher on the UFOs/Nukes-connection. Visit his website.
Civil research (books)
Hastings, R. (2017): UFOs & Nukes: Extraordinary Encounters at Nuclear Weapons Sites. 2nd Edition.
Scientific papers
L. J. Hancock, I. M. Porritt, S. Grosvenor, L. Cates, and I. Okafor (2023): UAP Pattern Recognition Study. 1945-1975 US Military Atomic Warfare Complex. Download.
(This paper provides a view of the pattern of reported Unidentified Aerospace Phenomena (UAP) in the United States associated with the military atomic weapons complex between 1945 and 1975.)
Documentaries

Hastings, R. (2016): UFOs and Nukes: The Secret Link Revealed. Apple TV. Imdb. Trailer/rent on Vimeo.
With research Robert Hastings.
With Robert Jamison, David Schindele, and Dr. Robert Jacobs.