Archer, Steven R.; Andersen, Erik M.; Predick, Katharine I.; Schwinning, Susanne; Steidl, Robert J.; Woods, Steven R. (2017), Briske, David D. (ed.), "Woody Plant Encroachment: Causes and Consequences", Rangeland Systems, Springer Series on Environmental Management, Cham: Springer International Publishing, pp. 25–84, doi:10.1007/978-3-319-46709-2_2, ISBN978-3-319-46707-8, S2CID133015720
Hogan, C. Michael (2009). "Overgrazing". In Draggan, Sidney; Cleveland, Cutler J. (eds.). Encyclopedia of Earth. Washington, D.C.: National council for Science and the Environment.
Archer, Steven R.; Andersen, Erik M.; Predick, Katharine I.; Schwinning, Susanne; Steidl, Robert J.; Woods, Steven R. (2017), Briske, David D. (ed.), "Woody Plant Encroachment: Causes and Consequences", Rangeland Systems, Springer Series on Environmental Management, Cham: Springer International Publishing, pp. 25–84, doi:10.1007/978-3-319-46709-2_2, ISBN978-3-319-46707-8, S2CID133015720