\u0413\u041e\u0421\u0422 \u0420 8.641-2013
State system for ensuring the iniformity of measurements. State verification scheme for measuring instruments of the water solutions ion content by electrochemical methods (pX measuring instruments)
\u0413\u041e\u0421\u0422 \u0420 8.641-2008
State sysem for ensuring the iniformity of measurements. State verification scheme for measuring instruments of the water solutions ion content by electrochemical methods (pX measuring instruments)