German standard methods for the examination of water, waste water and sludge - Physical and physico-chemical parameters (group C) - Part 10: Calcit saturation of water (C 10)— 34 стр.
German standard methods for the examination of water, waste water and sludge; summary indices of actions and substances (group H); determination of acid and base capacity (H7)— 10 стр.
Ductile iron pipes, fittings, accessories and their joints for sewerage application - Requirements and test methods; German version EN 598:1994— 24 стр.
Central drinking water supply - Guide lines regarding requirements for drinking water, planning, construction, operation and maintenance of plants - Technical rule of the DVGW— 10 стр.