1. Word Gas Meter Report,2007
2. ISO 10012:2003 Measurement Management Systems – Requirements for Measurement Processes and Measuring Equipment.
3. OIML, International Vocabulary of Terms in Legal Metrology: VIML 2.13, 2000.
4. Directive 2004/22/EC of The European Parliament and of the Council OF 31 March 2004 on Measuring Instruments (“The Measuring Instruments Directive”).
5. WELMEC guide 8.1 (issue 1): Guide on Terms and Definitions in MID and their Relation to Terms Defined in Other International Metrologically Relevant Documents, June 2006.