DIN 13940-1
DIN 13940-1 Dentistry; dental handpieces; coupling dimensions (ISO 3964:1982); german version EN 23964:1989
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/1990
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/1990