Piotrowska , Krystyna, Elżbieta Weryszko-Chmielewska, Piotr Rapiejko, Małgorzata Puc, Małgorzata Malkiewicz, Kazimiera Chłopek, and Dorota Myszkowska. 2007. “The Analysis of Hazel Pollen Count in Selected Cities of Poland in 2007”. Alergoprofil 3 (2), 30-34. https://www.journalsmededu.pl/index.php/alergoprofil/article/view/10.