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Viera Vanková
Department of Ecology and Environmental Sciences, Fakulty of Natural Sciences, Constantiene the Philosopher University, Nitra, Tr. A Hlinku 1, 949 74 Nitra, Slovak Republic
Peter Petluš
Department of Ecology and Environmental Sciences, Fakulty of Natural Sciences, Constantiene the Philosopher University, Nitra, Tr. A Hlinku 1, 949 74 Nitra, Slovak Republic