@inbook {3967,
	title = {Calicioid lichens and fungi},
	booktitle = {Nordic Lichen Flora },
	volume = {1},
	year = {1999},
	pages = {20-94},
	publisher = {The Nordic Lichen Society},
	organization = {The Nordic Lichen Society},
	address = {Uddevalla, Sweden},
	issn = {9197286338},
	author = {Tibell, L.},
	editor = {Ahti, T. and et al}
}
@article {2510,
	title = {The lichen genus Usnea in East Fennoscandia. III. The shrubby species},
	journal = {Annales Botanici Fennici},
	volume = {36},
	year = {1999},
	pages = {235-256},
	url = {http://www.sekj.org/PDF/anbf36/anbf36-235p.pdf},
	author = {Halonen, P. and Myllys, L. and Ahti, T. and Petrova, O.V.}
}
