Inventor: Niekerk, Johan Van
Inventor: Koning, Lammert
Inventor: Koning, Lammert
Inventor: Koning, Lammert
Inventor: van Niekerk, Johan
Inventor: van Niekerk, Johan
Inventor: Koning, Lammert
Inventor: Koning, Lammert
Inventor: Koning, Lammert
Inventor: van den Burg, Gerardus Pieter