Everhart, Sydney E., Joseph S. Ely, and Harold W. Keller. "Evaluation of Tree Canopy Epiphytes and Bark Characteristics Associated with the Presence of Corticolous Myxomycetes." Botany-Botanique 87, no. 5 (2009): 509-517.

Everhart, Sydney E., Harold W. Keller, and Joseph S. Ely. "Influence of Bark Ph on the Occurrence and Distribution of Tree Canopy Myxomycete Species." Mycologia 100, no. 2 (2008): 191-204.

Everhart, Sydney E., and Harold W. Keller. "Life History Strategies of Corticolous Myxomycetes: The Life Cycle, Plasmodial Types, Fruiting Bodies, and Taxonomic Orders." Fungal Diversity 29 (2008): 1-16.

Kilgore, Courtney M., Harold W. Keller, Sydney E. Everhart, Angela R. Scarborough, Kenneth L. Snell, Melissa S. Skrabal, Charly Pottorff, and Joseph S. Ely. "Tree Canopy Research and Student Experiences Using the Double Rope Climbing Method." Journal of the Botanical Research Institute of Texas 2, no. 2 (2008): 1309-1336.

Fanning, Erin, Joseph S. Ely, Thorsten H. Lumbsch, and Harold W. Keller. "Vertical Distribution of Lichen Growth Forms in Tree Canopies of Great Smoky Mountains National Park." Southeastern Naturalist 6, no. sp2 (2007): 83-88.

Scarborough, Angela R., and Harold W. Keller. Ecological Distribution of Tree Canopy Myxomycetes Sampled from Great Smoky Mountains National Park and Pertle Springs, Johnson County, Missouri. University of Central Missouri, 2005.

Gaither, Thomas W., and Harold W. Keller. "Taxonomic Comparison of Diachea subsessilis and D. deviata (Myxomycetes, Didymiaceae) Using Scanning Electron Microscopy." Systematics and Geography of Plants 74, no. 1 (2004): 217-230.

Keller, Harold W., Melissa S. Skrabal, Uno H. Eliasson, and Thomas W. Gaither. "Tree Canopy Biodiversity in the Great Smoky Mountains National Park: Ecological and Developmental Observations of a New Myxomycete Species of Diachea." Mycologia 96, no. 3 (2004): 537-547.

Keller, Harold W.. "Tree Canopy Biodiversity: Student Reserach Experienced in Great Smoky Mountains National Park." Systematics and Geography of Plants 74, no. 1 (2004): 47-65.

Davison, Paul G., and Harold W. Keller. "Vertical Distribution of Liverworts Within the Forest Canopy in the Southern Appalachians: Contribution to the All Taxa Biodiversity Inventory of the Great Smoky Mountains National Pa." Evansia 21, no. 2 (2004): 79-87.

Keller, Harold W., Paul G. Davison, Christopher H. Haufler, and Damon B. Lesmeister. "Polypodium Appalachianum: An Unusual Tree Canopy Epiphyte in the Great Smoky Mountains National Park." American Fern Journal 93, no. 1 (2003): 36-41.

Ciegler, Alex, Uno H. Eliasson, and Harold W. Keller. "Tree Canopy Lichens of the Great Smoky Mountains National Park." Evansia 20, no. 4 (2003): 114-127.

Snell, Kenneth L., Harold W. Keller, and Uno H. Eliasson. "Tree Canopy Myxomycetes and New Records from Ground Sites in the Great Smoky Mountains National Park." Castanea: The Journal of the Southern Appalachian Botanical Society 68, no. 2 (2003): 97-108.

Snell, Kenneth L., and Harold W. Keller. "Vertical Distribution and Assemblages of Corticolous Myxomycetes on Five Tree Species in the Great Smoky Mountains National Park." Mycologia 95, no. 4 (2003): 565-576.

Keller, Harold W., and Melissa S. Skrabal. "Discovery of a New Obligate Tree Canopy Myxomycete in the Great Smoky Mountains National Park." Inoculum 53, no. 2 (2002): 1-4.

Keller, Harold W., and Kenneth L. Snell. "Feeding Activities of Slugs on Myxomycetes and Macrofungi." Mycologia 94, no. 5 (2002): 757-760.

Keller, Harold W.. "Trees of Great Smokies Provide Mountains of Opportunity for Student Reserachers." ATBI Quarterly 1, no. 1 (2000): 10-11.