@book {683,
	title = {American Arctic Lichens I. The Macrolichens},
	year = {1984},
	publisher = {Columbia University Press},
	organization = {Columbia University Press},
	issn = {0231058888, 9780231058889},
	author = {Thomson, John Walter and Bethia Brehmer}
}
@book {713,
	title = {American Arctic Lichens II. The Microlichens},
	year = {1997},
	publisher = {The University of Wisconsin Press.},
	organization = {The University of Wisconsin Press.},
	address = {Madison},
	issn = {299-13460-1},
	author = {Thomson, John Walter}
}
