Gruszka, Wojciech. “The Concept of Lichen Refugia Classification. A Proposal Based on the Case Study of Krajeńskie Lakeland, Poland”. Ecological Questions 27 (December 19, 2017): 65–75. Accessed May 22, 2025. https://apcz.umk.pl/EQ/article/view/EQ.2017.028.