ORIGINAL RESEARCH
Water on the Fen Mire as a Problem
in the Protection of Globally Threatened
Species: Long-Term Changes
in Aquatic Warbler Numbers
Grzegorz Grzywaczewski1, Andrzej Bochniak2, Jarosław Wiącek3,
Paweł Łapiński4, Federico Morelli5,6
Pol. J. Environ. Stud. 2017;26(2):613-618