Ключевые слова: background, black, blank, book, bookshelf, classics, closed, collection, colorful, cover, document, education, expertise, gray, group, hardcover, heap, image, information, knowledge, large, learning, library, literature, many, monochrome, multi, nobody, object, objects, order, paper, pile, reading, research, row, school, series, single, spine, stack, study, textbook, variation, white, wisdom,