http://www.alyoshin.ru/Files/publika/khan_archi/khan_archi_2_052.html

http://ru.wikipedia.org/wiki/%D0%9C%D0%B8%D0%BB%D1%8E%D1%82%D0%B8%D0%BD,_%D0%9D%D0%B8%D0%BA%D0%BE%D0%BB%D0%B0%D0%B9_%D0%90%D0%BB%D0%B5%D0%BA%D1%81%D0%B0%D0%BD%D0%B4%D1%80%D0%BE%D0%B2%D0%B8%D1%87