1. Monteith DT, Evans CD (1998) 10 year UKAWMN report analysis and interpretation of results April 1988–March 1998. ENSIS Publishing, London. March 2000 ISBN 1 871275 26 1
2. Aquacheck (2007) International proficiency testing for chemical analytical laboratories http://www.lgcpt.com/scheme.aspx?SchemeID=77
3. Grubbs F (1969) Procedures for detecting outlying observations in samples. Technometrics 11(1):1–21
4. ISO/TR 13530 (1999) “Guide to analytical quality control for water analysis”
5. Timmerman JG, Gardner MJ, Ravenscroft JE (1996) UN/ECE task force on monitoring and assessment, vol 4–Quality assurance ISBN 9036945860