@article {2483, title = {Key to European Usnea species}, journal = {Bibliotheca Lichenologica}, volume = {100}, year = {2009}, pages = {419-462}, url = {http://home.comcast.net/~nwlichens/Randlane_et\%20al_2009Usnea.pdf}, author = {Randlane, T. and T{\~o}rra, T. and Saag, A. and Saag, L.} } @article {2474, title = {Phylogenetic relations of European shrubby taxa of the genus Usnea}, journal = {Lichenologist}, volume = {43}, year = {2011}, pages = {427-444}, issn = {0024-2829}, doi = {10.1017/S0024282911000375}, author = {Saag, L. and T{\~o}rra, T. and Saag, A. and Del-Prado, R. and Randlane, T.} }