Dic Sonneveld ( NL) is wolrdwide famous for his very tricky 3 and 4 piece burrs in many different and difficult variations; His may be most difficult design, a framed burr with level 98 ( it means there are 98 moves necessary to open the first piece) was dedicated by him to the craftsman Josef Pelikan (CZ) and he put it up for an auction for the flood-disaster in czech republic