Hurta, V., and M. Kmeťová. “A Contribution to the Knowledge of Selected Ele-Ment Contents in Food Products and Sycamore Leaves Near the Paper Mill Industry”. Oecologia Montana 26, no. 2 (December 1, 2017): 55-58. Accessed September 21, 2020. https://om.vuvb.uniza.sk/index.php/OM/article/view/302.