Ключевые слова: book, book day, bookmark, business, closeup, college, concept, copy space, day, diploma, education, encyclopedia, exam, information, knowledge, library, literature, math, modern, notepad, office, open, page, pencil, publication, read, reading, research, school, science, sheet, smart, soft focus, student, studying, symbol, textbook, university, white, wisdom, work, workbook, world, world book day, writing, yellow,