1. United States Pharmacopoeia, Physical Test Method 645: Water conductivity.
2. European Pharmacopoeia, Edition 6.4. Section 2.2.38 Conductivity, Monographs 1927 & 0169.
3. European Directorate for the Quality in Medicine and Healthcare, at http://www.edqm.eu/en/International-Harmonisation-614.html.
4. Guide for Ultra Pure Water Systems Used in Semiconductor Processing, at http://electronics.ihs.com/collections/semi/.
5. Standard Guide for Ultra-Pure Water Used in the Electronics and Semiconductor Industries, A. International, D 5127-07, 2007.