NF P94-510-1:2007 Geotechnical investigation and testing - Sampling methods and groundwater measurements - Part 1 : technical principles for execution.
2007NF P94-510-1:2007 Geotechnical investigation and testing - Sampling methods and groundwater measurements - Part 1 : technical principles for execution.
1996NF P94-157-2:1996 Soils : investigation and testing. In situ pore pressure measurement. Part 2 : pore pressure meter.