Dąbrowska-Zapart , K., and K. Chłopek. “The Analysis of Birch Pollen Count in Sosnowiec in 2010”. Alergoprofil, Vol. 6, no. 3, Sept. 2010, pp. 26-28, https://www.journalsmededu.pl/index.php/alergoprofil/article/view/200.