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Kazimierz Gaj
Institute of Environment Protection Engineering, Wroclaw University of Technology, ul. Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland, phone +48 71 320 35 84, fax +48 71 328 29 80
Hanna Cybulska-Szulc
Institute of Environment Protection Engineering, Wroclaw University of Technology, ul. Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland, phone +48 71 320 35 84, fax +48 71 328 29 80