That looks good, and I'd guess that some sightings are of military aircraft, but the theory that all sightings are of military aircraft falls flat with me.
Especially when you read this book, which also is well-researched citing sources wherever possible.
I thought that was Alien Agenda
J Allen Hynek - The Edge of Reality: A Progress Report on Unidentified Flying Objects
Timothy Green Beckley - Mystery of the Men in Black: The UFO Silencers
I'll add more in a bit, but these are the ones I always recommend and find myself referring to for reference material.