Triangle Craft Books?

For many reasons and for many decades I dismissed all ET/UFO talk but after TTS, Commander Fraver, and especially Ryan Graves (because he’s so very easy to look at), I began looking into it. It’s really difficult for me to reject some of these claims and evidence. There’s only a few people who know about my interest in this.

The recurring sightings of huge triangle-shaped craft is one of the most compelling civilian phenomena to me. Are there any people who have researched this specifically? So far I’ve heard stories here and there but I’d like to read a book that compiles all of this information.