Stairs and guard rails for stairs for outside and inside area on seagoing ships – Fundamental requirements
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/2003

Stairs and guard rails for stairs for outside and inside area on seagoing ships – Fundamental requirements
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 03/01/2013