"extraterrestrial spacecraft" . "Extraterrestrial Hypothesis" . . "Extraterrestrial hypothesis" . "extraterrestrial hypothesis" . "alien visitation" . "extraterrestrial beliefs" . "extraterrestrial alien visitors" . . "extraterrestrials" . . "extraterrestrial visitations" . "extraterrestrial in origin" . "Extraterrestrial hypothesis" . "extraterrestrial explanation" . . "ETH" . "extraterrestrial visitors" . . .