Authors
Mirosław Wiatkowski
Department of Land Protection, University of Opole, Opole, Poland
Izabela Czerniawska-Kusza
Department of Land Protection, University of Opole, Opole, Poland
© 2009 Mirosław Wiatkowski, Izabela Czerniawska-Kusza, published by University of Gdańsk
This work is licensed under the Creative Commons License.