1. Using Enviropod low altitude imagery to inventory building surface materials for an acid rain study: A Baltimore example;Ellefsen,1987
2. Results of an experiment using the Enviropod Camera System to inventory building surface materials in Cincinnati, Ohio;Ellefsen,1988
3. Development of an Inventory of Materials Potentially Sensitive to Ambient Atmospheric Acidity in the South Coast Air Basin;Ellefsen;Valley Research Corporation report prepared for California Air Resources Board,1989
4. Urban Terrain Classification System, American, British, Canadian, Australian Armies Standardization Program, Quadripartite Advisory Publications 32;Ellefsen;U.S. Army TRADOC Systems Analysis Activity,1983
5. Urban Terrain Analysis;Ellefsen,1981