Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Gutter, Martien
Inventor: Gutter, Martien
Inventor: Gutter, Martien
Inventor: Ernest D. Williams