DIN 85004-9
DIN 85004-9 Pipelines of copper-nickel-alloys - Part 9: General principles for the radiographic examination; Text in German and English
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/2008
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/2008