Building hardware – Controlled door closing devices – Part 1: Surface (top) mounted door closer with crank drive and spiral spring (pot-type door closer)
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/2015

Building hardware – Controlled door closing devices with hydraulic damping – Part 1: Surface(top) mounted door closer with crank drive and spiral spring (pot-type door closer)
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 05/01/1997