@article {2980,
	title = {Factors Involved in the Persistence of Montane Treeless Balds},
	journal = {Ecology},
	volume = {38},
	year = {1957},
	month = {January},
	pages = {140-142},
	keywords = {Ecosystem, Grassy balds},
	author = {Billings, W. D and Mark, A. F}
}
@article {3663,
	title = {A Comparison of Virgin Spruce-Fir Forest in the Northern and Southern Appalachian System},
	journal = {Ecology},
	volume = {32},
	year = {1951},
	month = {January},
	pages = {84-103},
	keywords = {Ecosystem, Flora -- Classification and description, Trees -- Classification and description, Trees -- Growth},
	author = {Oosting, H. J and Billings, W. D}
}
@article {2979,
	title = {Bark Factors Affecting the Distribution of Corticolous Bryophytic Communities},
	journal = {The American Midland Naturalist},
	volume = {20},
	year = {1938},
	note = {Illustrations, Maps},
	month = {September},
	pages = {302-330},
	keywords = {Flora, Liverworts, Mosses, Trees},
	author = {Billings, W. D and Drew, William B}
}
@article {2423,
	title = {Winter Key to the Trees of Eastern Tennessee},
	journal = {The Journal of the Southern Appalachian Botanical Club},
	volume = {2},
	year = {1937},
	pages = {29-44},
	keywords = {Trees -- Classification and description},
	author = {Billings, W. D and Cain, Stanley A and Drew, William B}
}
