1. BIPM, IEC, IFCC, ISO, ILAC, IUPAC, IUPAP, OIML (2008) International Vocabulary of Metrology; basic and general concepts and associated terms—VIM, JCGM 200: 3rd edn. Available online at: http://www.bipm.org/en/publications/guides/vim.html
2. ISO/IEC 17025 (2004) General requirements for the competence of testing and calibration laboratories. International Organization for Standardization, Geneva
3. Heydorn K, Madsen BS (2005) Accred Qual Assur 10:403–408
4. Anglov T et al (2003) Accred Qual Assur 8:225–230
5. Heydorn K, Nørgaard K (1973) J Radioanal Chem 15:683–693