1. Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States Author/Creator: Young, H. L. Publication/Creation: Denver, CO : For sale by Books and Open-File Reports, U.S. Geological Survey Resource Type: Book Access & Availability: Loading
2. Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States Author/Creator: Young, H. L., author Publication/Creation: Washington : U.S. Department of the Interior, U.S. Geological Survey, 1992 Resource Type: Book Access & Availability: Loading