O.  Gilbert, Lichens. London: HarperCollins, 2000, p. 288.

M.  Schultz and Büdel, B., ?Key to the genera of the Lichinaceae?, The Lichenologist, vol. 34, pp. 39-62, 2002.

G.  Brown, ?Saxicolous and terricolous lichens from the foothills of northern Oman?, Nova Hedwigia, vol. 75, pp. 177-188, 2002.

M.  Schultz, ?The saxicolous and terricolous, cyanobacterial lichens of Socotra (Yemen, Indian Ocean)?, Nova Hedwigia, vol. 77, pp. 73-97, 2003.

?Index Fungorum [taxonomy information]?, 2008.

T.  H. Lumbsch and Huhndorf, S. M., ?Outline of Ascomycota - 2007. [Classification Information]?, Myconet, vol. 13, pp. 1-58, 2007.