DIN 18381:2016 德國建筑包工合同程序(VOB). 第C部分: 建筑包工合同通用技術規范(ATV). 建筑內燃氣, 供水和排水管道工程建設
German construction contract procedures (VOB) - Part C: General technical specifications in construction contracts (ATV) - Installation of gas, water and drainage pipework inside buildings