Dagley, C.M. Performance of Planted Herbaceous Species in Longleaf Pine (Pinus palustris Mill.) Plantations: Overstory Effects of Competition and Needlefall, text, July 3, 2001; (https://digital.library.unt.edu/ark:/67531/metadc738203/m1/1/: accessed September 24, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .