@article {2495,
	title = {Systematics of the Usnea fragilescens aggregate and its distribution in Scandinavia},
	journal = {Nordic Journal of Botany},
	volume = {7},
	year = {1987},
	pages = {479-495},
	issn = {0107055X},
	doi = {10.1111/njb.1987.7.issue-410.1111/j.1756-1051.1987.tb00969.x},
	author = {Clerc, P.}
}
