Polish Journal of Environmental Studies
Polish Journal of Environmental Studies > 2000 > 9 > 6 > 511-515
Polish Journal of Environmental Studies > 2000 > 9 > 6 > 517-522
Polish Journal of Environmental Studies > 2000 > 9 > 6 > 455-462
Polish Journal of Environmental Studies > 2000 > 9 > 6 > 523-530