Pärtel, Kadri, Kadri Põldmaa, Bellis Kullman, Ave Suija, Piret Lõhmus, and Motiejūnaitė Jurga. 2008. “ Lichens and Lichenicolous Fungi”. Folia Cryptogamica Estonica 44 (September):155-59. https://ojs.utlib.ee/index.php/FCE/article/view/13719.