KOKEŠ, J.,
Světlana ZAHRÁDKOVÁ, Denisa NĚMEJCOVÁ, Jan HODOVSKÝ,
Jiří JARKOVSKÝ and T. SOLDÁN. The PERLA system in the Czech Republic: a multivariate approach for assessing the ecological status of running waters.
Hydrobiologia. Netherlands: Kluwer Academic Publishers, 2006, vol. 2006, No 566, p. 343-354, 11 pp. ISSN 0018-8158.