1. Haze in the Grand Canyon: An Evaluation of the Winter Haze Intensive Tracer Experiment;Duce,1990
2. Protecting Visibility in National Parks and Wilderness Areas;Duce,1993
3. The Colorado plateau;Durrenberger;Annals of the Association of American Geographers,1972
4. Re: Promulgation of Regional Haze Rulemakings, 1 July 2010 Letter to G. McCarthy, USEPA, from WEST Associates;Eklund,2010
5. Recommendations for Improving Western Vistas;Grand Canyon Visibility Transport Commission,1996