1. Umbrellas and flagships: efficient conservation surrogates or expensive mistakes?;Andelman;Proc. Natl. Acad. Sci. USA,2000
2. Population constraints associated with the use of black rhinos as an umbrella species for desert herbivores;Berger;Conserv. Biol.,1997
3. Bidwell, T.G., Engle, D.M., Mosely, M.E., Masters, R.E., 2002. Invasion of Oklahoma rangelands and forests by eastern redcedar and ashe juniper. Oklahoma Cooperative Extension Service Circular E-947, Stillwater, Oklahoma, USA.
4. Numerical Ecology with R;Borcard,2011
5. How can we reverse the northern bobwhite population decline?;Brennan;Wildl. Soc. Bull.,1991