Clasificación de la Biblioteca del CongresoSD391.S52

21st century(10) adventure(44) Africa(24) agriculture(14) American(7) American West(8) animals(13) archaeology(5) biography(35) biology(59) botany(145) California(122) Canada(55) Canadian(27) children's(13) children's literature(7) climate change(10) climbing(17) community(7) conservation(69) culture(8) ecology(166) ecosystems(7) England(7) environment(142) environmental(13) environmentalism(29) exploration(11) extinction(6) family(8) fantasy(7) folklore(6) food(8) forest(37) garden(5) gardening(47) geography(9) Grade 2(6) historical(5) history(130) horticulture(15) how-to(5) imagination(14) informational(20) insects(5) journalism(5) juvenile(5) math(5) mental illness(10) multicultural(5) mystery(5) narrative nonfiction(10) Native American(6) natural resources(6) natural science(8) nature(373) nature writing(15) North America(10) Northwest(7) outdoors(16) photography(14) picture book(86) popular science(5) poverty(5) reference(14) science(199) science nonfiction(6) scientists(8) sustainability(15) travel(10) tree(22) trees(582) usa(21) wildlife(5) wood(16) woods(6)