Hogan, C. Michael (2008). Stromberg, Nicklas (ed.). Quercus kelloggii. GlobalTwitcher. Archived from the original on September 24, 2009. Retrieved October 17, 2008.
Hogan, C. Michael (2008). Stromberg, Nicklas (ed.). Quercus kelloggii. GlobalTwitcher. Archived from the original on September 24, 2009. Retrieved October 17, 2008.