@book{cbdu15000,
           title = {Extr{\'a}ordyn{\'a}ryine z Poczty Ces{\'a}rskiey wi{\'a}domo{\'s}ci. z Kr{\'a}kow{\'a} 20. Septembris 1687. },
          number = {1500},
         address = {Krak{\'o}w},
             url = {http://cbdu.ijp.pan.pl/id/eprint/15000/}
}