1. Ground-water pumpage in the Willamette lowland regional aquifer system, Oregon and Washington, 1990 Author/Creator: Collins, C. A. 1944- (Charles Alexander), author Publication/Creation: Portland, Oregon : U.S. Geological Survey, 1996 Resource Type: Book Access & Availability: Loading
2. Estimated average annual ground-water pumpage in the Portland Basin, Oregon and Washington 1987-88 Author/Creator: Collins, C. A. 1944- (Charles Alexander), author Publication/Creation: Portland, Oregon : U.S. Geological Survey, 1994 Resource Type: Book Access & Availability: Loading
3. Ground-water pumpage from the Columbia Plateau Regional Aquifer System, Oregon, 1984 Author/Creator: Collins, C. A. 1944- (Charles Alexander), author Publication/Creation: Portland, Oregon : U.S. Geological Survey, 1987 Resource Type: Book Access & Availability: Loading