Printzen, Christian, and Tor Tonsberg. "Bacidia lobarica (Bacidiaceae, Lecanorales) sp. nov., a Sorediate Lichen from the Southeastern U.S.A." The Bryologist 110, no. 3 (2007): 487-489.

Tonsberg, Tor. "Notes on the Lichen Genus Lepraria in Great Smoky Mountains National Park, Southeastern North America: Lepraria lanata and L. salazinica spp. nov." Opuscula Philolichenum 4 (2007): 51-54.

Hopkins, Bjarke, and Tor Tonsberg. "Notes on Botryolepraria lesdainii in North America." Evansia 23, no. 2 (2006): 34-35.