1. Potential Natural Vegetation of the Conterminous United States;Kuchler,1964
2. A predictive model to locate ancient forests in the Cross Timbers of Osage County, Oklahoma
3. Characteristics of the Keystone Ancient Forest Preserve, an old-growth forest in the Cross Timbers of Oklahoma;Clark;Nat. Area J.,2005
4. Fire, Drought, and Human History near the Western Terminus of the Cross Timbers, Wichita Mountains, Oklahoma, USA