^Vainio, E.A. (1890). "Étude sur la classification naturelle et la morphologie des Lichens du Brésil. Pars prima". Acta Societatis pro Fauna et Flora Fennica (in Latin). 7 (1): 1–247.
^Schultz, M.; Porembski, S.; Büdel, B. (2000). "Diversity of rock‐inhabiting cyanobacterial lichens: studies on granite inselbergs along the Orinoco and in Guyana". Plant Biology. 2 (4): 482–495. doi:10.1055/s-2000-5951.
^Jørgensen, P.M. (1990). "The lichen genus Pterygiopsis in northern Europe". The Lichenologist. 22 (3): 213–217. doi:10.1017/S0024282990000238.
^Schultz, M. (2004). "Pterygiopsis pulchra, a remarkable new species of the Lichinaceae from south-eastern Yemen". Bibliotheca Lichenologica. 88: 555–560.