Roby, G. A. (1976). Mechanical methods of chaparral modification. Washington, D.C. : U.S. Dept. of Agriculture, Forest Service.
Style de citation Chicago (17e éd.)Roby, George A. Mechanical Methods of Chaparral Modification. Washington, D.C. : U.S. Dept. of Agriculture, Forest Service, 1976.
Style de citation MLA (8e éd.)Roby, George A. Mechanical Methods of Chaparral Modification. Washington, D.C. : U.S. Dept. of Agriculture, Forest Service, 1976.
Style de citation IICA/CATIERoby, G. A. 1976. Mechanical methods of chaparral modification. Washington, D.C. : U.S. Dept. of Agriculture, Forest Service.