@article {3596,
	title = {Acid Deposition Alters Red Spruce Physiology: Laboratory Studies Support Field Observations},
	journal = {Canadian Journal of Forest Research},
	volume = {23},
	year = {1993},
	month = {March},
	pages = {380-386},
	keywords = {Acid rain, Red spruce, Soil acidity},
	author = {McLaughlin, Samuel B and Tjoelker, Mark G and Roy, W. Kelly}
}
@article {3597,
	title = {Growth and Physiological Changes in Red Spruce Saplings Associated with Acidic Deposition at High Elevations in the Southern Appalachians, USA},
	journal = {Forest Ecology and Management},
	volume = {51},
	year = {1992},
	month = {August},
	pages = {43-51},
	keywords = {Acid rain, Red spruce, Soil acidity, Trees -- Decay},
	url = {http://dx.doi.org/10.1016/0378-1127(92)90470-T},
	author = {McLaughlin, Samuel B and Tjoelker, Mark G}
}
@article {4986,
	title = {Seasonal variation in nitrate reductase activity in needles of high-elevation red spruce trees},
	journal = {Canadian Journal of Forest Research},
	volume = {22},
	year = {1992},
	note = {Tables},
	pages = {375-380},
	publisher = {NRC Research Press},
	address = {Ottawa, Ontario, Canada},
	keywords = {Pollution, Red spruce, Soils, Spruce-Fir forests},
	author = {Tjoelker, Mark G and McLaughlin, Samuel B and DiCosty, R. J and Lindberg, Steven E and Norby, R. J}
}
@article {4656,
	title = {Increased Dark Respiration and Calcium Deficiency of Red Spruce in Relation to Acidic Deposition at High-elevation Southern Appalachian Mountain Sites},
	journal = {Canadian Journal of Forest Research},
	volume = {21},
	year = {1991},
	pages = {1234-1244},
	keywords = {Red spruce, Soil acidity, Topography, Trees -- Growth},
	author = {McLaughlin, Samuel B and Andersen, Christian P and Hanson, Paul J and Tjoelker, Mark G and Roy, W. Kelly}
}
