Puc , M., M. I. Puc, A. Lipiec, and P. Rapiejko. “Dynamics of Alder and Birch Pollen Seasons in Szczecin and Warsaw (2008?2010)”. Alergoprofil, Vol. 7, no. 3, Sept. 2011, pp. 33-40, https://www.journalsmededu.pl/index.php/alergoprofil/article/view/281.