Neufeld, Howard S., Seth J. Peoples, Alan W. Davidson, Arthur H. Chappelka, Greg L. Somers, Jill E. Thomley, and Fitzgerald L. Booker. "Ambient Ozone Effects on Gas Exchange and Total Non-Structural Carbohydrate Levels in Cutleaf Coneflower                        (Rudbeckia laciniata L.) Growing in Great Smoky Mountains National                        Park." Environmental Pollution 160, no. January (2012): 74-81.

Grulke, N. E., Howard S. Neufeld, Alan W. Davison, M. Roberts, and Arthur H. Chappelka. "Stomatal Behavior of Ozone-Sensitive and -Insensitive Coneflowers (Rudbeckia laciniata var. digitata) in Great Smoky Mountains National Park." New Phytologist 173, no. 1 (2007): 100-109.

Souza, Lara, Howard S. Neufeld, Arthur H. Chappelka, Kent O. Burkey, and Alan W. Davison. "Seasonal Development of Ozone-Induced Foliar Injury on Tall Milkweed (Asclepias exaltata) in Great Smoky Mountains National Park." Environmental Pollution 141, no. 1 (2006): 175-183.

Burkey, Kent O., Howard S. Neufeld, Lara Souza, Arthur H. Chappelka, and Alan W. Davison. "Seasonal Profiles of Leaf Ascorbic Acid Content and Redox State in Ozone-Sensitive Wildflowers." Environmental Pollution 143, no. 3 (2006): 427-434.

Neufeld, Howard S., Arthur H. Chappelka, Greg L. Somers, Kent O. Burkey, Alan W. Davidson, and Peter L. Finkelstein. "Visible Foliar Injury Caused by Ozone Alters the Relationship between SPAD Meter Readings and Chlorophyll Concentrations in Cutleaf Coneflower." Photosynthesis Research 87, no. 3 (2006): 281-286.

Finkelstein, Peter L., Alan W. Davison, Howard S. Neufeld, Tilden P. Meyers, and Arthur H. Chappelka. "Sub-Canopy Deposition of Ozone in a Stand of Cutleaf Coneflower." Environmental Pollution 131, no. 2 (2004): 295-303.

Davison, Alan W., Howard S. Neufeld, Arthur H. Chappelka, K. Wolff, and Peter L. Finkelstein. "Interpreting Spatial Variation in Ozone Symptoms Shown by Cutleaf Cone Flower, Rudbeckia laciniata L." Environmental Pollution 125, no. 1 (2003): 61-70.

Chappelka, Arthur H., Howard S. Neufeld, Alan W. Davison, Greg L. Somers, and James R. Renfro. "Ozone Injury on Cutleaf Coneflower (Rudbeckia laciniata) and Crown-Beard (Verbesina occidentalis) in Great Smoky Mountains National Park." Environmental Pollution 125, no. 1 (2003): 53-59.

Neufeld, Howard S., E. H. Lee, James R. Renfro, and David W. Hacker. "Seedling Insensitivity to Ozone for Three Conifer Species Native to Great Smoky Mountains National Park." Environmental Pollution 108, no. 2 (2000): 141-151.

Horton, J. L., and Howard S. Neufeld. "Photosynthetic Responses of Microstegium vimineum (Trin.) A. Camus, a Shade-Tolerant, C4 Grass, to Variable Light Environments." Oecologia 114, no. 1 (1998): 11-19.

Neufeld, Howard S., Henry E. Lee, James R. Renfro, David W. Hacker, and Ben-Hui Yu. "Sensitivity of Seedlings of Black Cherry (Prunus serotina Ehrh.) to Ozone in Great Smoky Mountains National Park. I. Exposure-Response Curves for Biomass." New Phytologist 130, no. 3 (1995): 447-459.

Neufeld, Howard S., and James R. Renfro. Sensitivity of Sycamore Seedlings (Platanus occidentalis) to Ozone in Great Smoky Mountains National Park Data from 1989. U. S. Department of the Interior, National Park Service, 1993.

Hacker, David W., James R. Renfro, and Howard S. Neufeld. Sensitivity of Native Plant Species to Elevated Levels of Ozone In Third Annual Southern Appalachian Man and the Biosphere Conference. Gatlinburg, TN: Tennessee Valley Authority, 1992.