Ключевые слова: alte, back, background, blank, book, booklet, bookmark, catalog, closed, closeup, college, colors, concept, cover, document, education, empty, green, handbook, hardcover, idea, information, isolated, knowledgebase, learning, library, literacy, literature, multicolored, novel, object, open, page, paper, publication, read, school, single, space, stack, story, study, text, textbook, wisdom,