These folks did some excellent work, not to mention, the law of one material.
This footage just newly been uploaded to YouTube - it's a television interview with Carla Rueckert and Don Elkins which is IMHO fascinating on several levels. An extreme number of subjects are talked about, you're able to see Carla and Don interact and discuss their findings, which is striking just how much of the things they discuss we're still talking about today, in addition to just how much ahead of time these were. You are able to hear many references by Don to his flight experience (he was an commercial pilot), amongst other things. Remember - the video is 33 years of age!
You will find five segments of eleven to fifteen minutes each. This is actually the first: