Modrzyńska , Katarzyna, Agnieszka Lipiec, Ewa Kalinowska, and Piotr Rapiejko. 2014. “Characteristics of Pollen Seasons of Hazel, Alder and Birch in Drawsko Pomorskie in 2014”. Alergoprofil 10 (2), 17-20. https://www.journalsmededu.pl/index.php/alergoprofil/article/view/794.