BLURB: Aliens: 15 Reasons to Believe: Paranormal UFO Sighting Cases That Still Mystify Non-Believers (Unexplained Mysteries of the World)

As we cannot see the limits to the universe, the possibility of the aliens seems certain. But, for some reason, we still have not seen them, or is that true?

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This book is for people who recognize those sentences as logical and grammatical.