1. Beier, U., Starkie, A. and Vehanen, T. 2007 Fishregional group 'Nordic' report. In N. Jepsen and D. Pont (eds), Intercalibration of fish-based methods to evaluate river ecological quality: report from an EU intercalibration pilot exercise, 176–92. Luxembourg. Office for Official Publications of the European Communities.
2. CEN 2003 Water quality—sampling of fish with electricity. European standard. Brussels. CEN.
3. CEN 2004 Water quality—guidance standard on the design of multimetric indices. Document CEN/TC 230 N 0504. Brussels. CEN.
4. CEN 2005a Water quality—guidance on the scope and selection of fish sampling methods. Brussels. CEN.