D. A.  Shepard, ?The Legitimacy of Quercus ellipsoidalis Based on a Populational Study of Quercus coccinea in Illinois?, Western Illinois UniversityEditor, 1993.

D. A.  Shepard, ?The occurrence of the scarlet oak, Quercus coccinea in northern Illinois?, Transactions of the Illinois State Academy of Science, vol. 84 (Suppl. 35) (Abstract)., 1991.

D. A.  Shepard, ?A review of the taxonomic status of Quercus ellipsoidalis and Quercus coccinea in the Eastern United States?, International Oak Journal, vol. 20, pp. 65-84, 2009.