шире смотрите https://ru.wikipedia.org/wiki/%D0%94%D0%B5%D0%BF%D0%BE%D1%80%D1%82%D0%B0%D1%86%D0%B8%D0%B8_%D0%BD%D0%B0%D1%80%D0%BE%D0%B4%D0%BE%D0%B2_%D0%B2_%D0%A1%D0%A1%D0%A1%D0%A0