Inventor: van Duijn, Jan Mark
Inventor: Hansen, Hans A.
Inventor: Saul, Robert Mark
Inventor: de Boer, Petrus
Inventor: de Boer, Petrus
Inventor: Bremer, Hinrich
Inventor: Troelstra, Johan
Inventor: Bakhuijzen, Arie
Inventor: Verhoef, Gijsbertus
Inventor: Crawford, James
Inventor: Van Andel, Otto Jan Robert