Draft Document – Soil, investigation and testing – Determination of the coefficient of water permeability – Part 2: Field tests
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 10/01/2003

Draft Document – Soil, investigation and testing – Determination of the coefficient of water permeability – Part 1: Field tests
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2011