DIN 2425-3:1980 Plans for Public Utilities, Water Resources and Long-distance Lines; Plans for Long-distance Pipelines, Technical Regulation of the DVGW (German Gas and Water Engineers Association)
1980DIN 2425-3:1980 Plans for Public Utilities, Water Resources and Long-distance Lines; Plans for Long-distance Pipelines, Technical Regulation of the DVGW (German Gas and Water Engineers Association)