Reference

**Reference Materials ** [|Encyclopedia Smithsonian] is an index of 140 topics for which the Smithsonian Institution offers online resources: American history, art, automobiles, butterflies, canines, cats, clocks, computers, dinosaurs, electricity, engineering, gardens, gems, inventors, jazz, Latino history, military history, musical instruments, oceanography, photography, political history, railroads, rain forests, sciences, sports, Stradivarius violins, telephones, television, World War I, zoology, and more. (Smithsonian Institution) [|alphaDictionary] Search 1065 Online English Dictionaries at Once!