Clasificación de la Biblioteca del CongresoTL789.2

1950s(112) 1960s(274) 1970s(73) abduction(88) accidents(60) adventure(204) alien(175) alien abduction(383) alien contact(32) Alien Encounters(21) aliens(623) ancient astronauts(58) astrophysics(59) autobiography(676) aviation(290) biographies(205) biography(2,878) careers(79) Challenger(84) children(211) children's(325) conspiracy(259) conspiracy theory(75) cosmology(66) cover-up(37) discovery(45) earth(71) engineering(436) exploration(501) extraterrestrial(55) Extraterrestrials(712) flight(84) futurism(89) gravity(37) history(4,356) history of science(202) informational(153) jobs(55) juvenile(182) juvenile literature(74) juvenile non-fiction(73) Mars(287) missiles(21) moon(1,528) nasa(2,923) occult(240) os(56) outer space(458) paranormal(923) photographs(80) photography(212) picture book(460) pilots(53) planets(202) popular science(75) pseudoscience(116) reference(462) rockets(461) Russia(159) science(5,745) science and technology(141) science fiction(643) science nonfiction(46) scientists(53) skepticism(62) solar system(318) space colonization(108) space exploration(2,628) space flight(1,456) space station(114) space stations(106) spacecraft(199) spaceship(38) speculation(61) stars(60) the 60s(24) universe(77) usa(468) weird(50) women(202)