@book {50,
	title = {Lichen Flora of the Greater Sonoran Desert Region},
	volume = {1},
	year = {2001},
	publisher = {Lichens Unlimited},
	organization = {Lichens Unlimited},
	address = {Tempe},
	author = {Thomas H. Nash_III and Bruce D. Ryan and Corinna Gries and Frank Bungartz}
}
