William L. Halvorson

Challenges to managing natural resource information

William L. Halvorson, 2005 .

Science and Ecosystem Management in the National Parks, William L. Halvorseon & Gary E. Davis, Editors, 1996. University of Arizona Press, Tucson. 384 pages. ISBN: 0-8265-1566-2. $40.00.

William L. Halvorson, G. Barrett, T. Barrett, 1996 .

Successional trends in Sonoran Desert abandoned agricultural fields in northern Mexico

Alejandro E. Castellanos, William L. Halvorson, I. Espejel, 2005 .