Authors
Irena Bielańska-Grajner
Department of Hydrobiology, University of Silesia, Katowice, Poland
Małgorzata Poznańska
Department of Invertebrate Zoology, Nicolaus Copernicus University, Toruń, Poland
© 2010 Irena Bielańska-Grajner, Małgorzata Poznańska, published by University of Gdańsk
This work is licensed under the Creative Commons License.