title: Incorporating concentration dependence in stable isotope mixing models: a reply to Robbins, Hilderbrand and Farley (2002).
authors.affiliation: Department of Earth Sciences, University of California, 1156 High St., Santa Cruz, CA, 95064, USA. pkoch@es-ucsc-edu.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Koch
authors.affiliation: U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 200 SW 35th St., Corvallis, OR, 97333, USA.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Phillips