Soil quality – Field tests – Part 7: Determination of infiltration rate by double ring infiltrometer
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2007

Soil quality – Field tests – Part 7: Determination of infiltration rate by double ring infiltrometer
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 08/01/2015