Inventor: Heemskerk, Harold
Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Bruinen, Edward
Inventor: Bruinen, Edward
Inventor: Stemkens, Henricus Godefridus Wilhelmus
Inventor: Spruit, Adrianus Theodorus
Inventor: Gutter, Martien
Inventor: Gutter, Martien
Inventor: Gutter, Martien
Inventor: Ernest D. Williams