Inventor: van Gaalen, Rene, de Boer, Huibert Anne
Inventor: Stevenson, John
Inventor: de Boer, Huibert Anne
Inventor: de Boer, Huibert Anne, van Gaalen, Rene
Inventor: de Boer, Huibert Anne
Inventor: Ritchie, John Stanley, Ritchie, Kathleen Anne
Inventor: Ruigrok, Wouter
Inventor: Ernest D. Williams