When I wrote my book about officially documented UFO reports, I fully expected the skeptics to react. That's why I was careful to focus only on the very best evidence from the most credible sources in UFOs: Generals, Pilots and Government Officials Go on the Record. Since 95 percent of all sightings are eventually identified, the book is concerned only with the remaining 5 percent - those UFO events that have been thoroughly investigated, involve multiple witnesses and ample data, but still cannot be explained. As an example, Brig. Gen. Jose Periera of Brazil, commander of air force operations until 2005, reports on an array of UFOs" observed over his country in 1986. Two pilots chased one of the objects for 30 minutes. Numerous other pilots saw the objects. Radar recorded them. Six jets were scrambled from two Brazilian air force bases to pursue them. Some of the pilots made visual contact corresponding to radar registrations. Both military and commercial pilots were involved. Onboard as well as ground radar systems confirmed the presence of the objects. "We have the correlation of independent readings from different sources," Periera writes. "These data have nothing to do with human eyes. When, along with the radar, a pilot's pair of eyes sees that same thing, and then another pilot's, and so on, the incident has real credibility and stands on a solid foundation."