Angular steel tanks for above ground storage of liquids with a flashpoint of more than 55 °C – Part 1: Principles for installation and test
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 06/01/2013

Steel tanks erected on site, for the above ground storage of hazardous flammable water polluting liquids of class A III and of non-flammable water polluting liquids; requirements and testing
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 09/01/1989