Можешь почитать...http://ru.wikipedia.org/wiki/%D0%A1%D0%BF%D0%B8%D1%81%D0%BE%D0%BA_%D0%B0%D1%82%D0%B0%D0%BA_%D0%98%D1%80%D0%B3%D1%83%D0%BD%D0%B0