Zduńczyk, A., M. Dziedzic, and M. Kukwa. “The Lichen Genus Pertusaria in Poland II. Secondary Chemistry of P. Flavida”. Folia Cryptogamica Estonica, Vol. 49, Oct. 2012, pp. 77-81, http://ojs.utlib.ee/index.php/FCE/article/view/13618.