^Ryan, B.D.; Nash, T.H. III (1993). "Lecanora section Placodium (lichenized Ascomycotina) in North America: new taxa in the L. garovaglii group". The Bryologist. 96 (3): 288–298. doi:10.2307/3243856. S2CID84348259.
^Kondratyuk, S.Y.; Zarei-Darki, B.; Khajeddin, S.J. (2012). "New species and combinations in the genus Protoparmeliopsis (Lecanoraceae, Lichenized Ascomycota)". Ukrainian Botanical Journal. 69 (6): 869–879.