B. J.  Coppins, Kondratyuk, S. Y., Etayo, J., and Cannon, P. F., ?Notes on lichenicolous species of Opegrapha s. lat. (Arthoniales) on Arthoniaceae and Verrucariaceae, with a key to British and Irish lichenicolous Opegraphaceae?, Lichenologist, vol. 53, pp. 159-169, 2021.