@article {1647,
	title = {The effects of SO2 on photosynthesis and carbohydrate transfer in the two Lichens: Collema polycarpon and Parmelia chlorochroa.},
	journal = {American Journal of Botany},
	volume = {71},
	year = {1984},
	pages = {986-998},
	author = {Fields, R.D. and StClair, L.L.}
}
