Inventor: de Gruyter, Andre
Inventor: ter Laak, Wendela Antoinette
Inventor: Koppe, Lubbertus H.
Inventor: ter Laak, Wendela Antoinette
Inventor: Beekenkamp, Annie Cornelia
Inventor: Beekenkamp, Annie Cornelia
Inventor: Beekenkamp, Annie Cornelia
Inventor: Johnson, Jr., Ozzie W.