Ключевые слова: academic, black, book, bookstore, collection, copybook, cover, design, document, education, elements, encyclopedia, graduated, graduation, hat, icon, illustration, information, isolated, knowledge, learning, library, line, literature, object, open, outline, page, paper, pile, read, reading, school, science, sign, stack, stand, store, study, studying, symbol, technology, text, textbook, thin, university, website,