The New book of knowledge : Vol. 1 Children's encyclopedias and dictionaries. 001 NEW A twenty-volume edition illustrated with maps, pictograms, and photographs, mostly in color. Entries are written by qualified specialists at reading levels ranging from ages six to twelve. Every volume is separately indexed with cross references to pertinent information found in other volumes of the set. New York : Grolier , 1973 1973 1973 Text 622 p. : eng