Silage and liquid manure containers, containers in biogas plants, bunker silos and trench silos – Part 22: Concrete blocks acting as lost formwork for silage and liquid manure containers, bunker silos and trench silos and liquid manure channels
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 09/01/2015

Silage and liquid manure containers – Part 22: concrete blocks acting as lost formwork
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 06/01/2004