Classificação da Biblioteca do Congresso dos E.U.A. (LCC)HE1-9990

19th century(605) accidents(54) airplanes(64) airport(57) American West(266) automobiles(91) aviation(419) biography(436) Boston(86) Britain(226) business(755) California(251) Canada(270) canals(280) cars(99) cities(100) commerce(59) communication(158) computers(145) culture(147) cycling(80) economic history(64) economics(305) engineering(149) England(260) environment(120) geography(137) Great Britain(138) history(5,195) industry(60) information technology(71) internet(211) journalism(150) London Underground(102) mail(132) management(118) maps(137) maritime(195) maritime history(132) media(469) media studies(72) nautical(70) New York(186) photographs(181) photography(314) planning(112) politics(287) post office(139) postage(14) postal(22) radio(481) railroading(59) reference(307) roads(249) shipping(182) ships(200) social history(139) sociology(238) stamps(528) subway(116) television(476) trains(878) travel(790) tube(22) U.S. History(124) uk(162) underground(102) urban(77) urban planning(191) urban studies(44) urbanism(56) us(94) usa(862) Virginia(75) world(99)