. . . . . . . . "Photographs introduce a variety of materials, such as wool, glass, and paper." . . . "Juvenile works" . "Juvenile works"@en . . . . . "Materials and their properties" . . . "Los materiales" . "Materials and their properties big book" . . . "Materials" . "Materials"@en . "Photographs as well as text introduce a variety of materials such as wool, glass, and paper." . . . . .