Soós, Áron, Réka Reichenbach, Szilvia Várallyay, Éva Bódi, Szabolcs Molnár, and Béla Kovács. “Elemental Content of Propolis Samples from Pest, Zala and Bács-Kiskun County (Hungary)”. Acta Agraria Debreceniensis, no. 72 (May 16, 2017): 149–153. Accessed June 30, 2022. https://ojs.lib.unideb.hu/actaagrar/article/view/1607.