Water quality in the Merced River above and below the El Portal Sewage Treatment Plant near Yosemite National Park, California, 1975-77 / by Ray J. Hoffman ; prepared in cooperation with the National Park Service (Open-file report ; 76-679)
Water quality in the Merced River above and below the El Portal Sewage Treatment Plant near Yosemite National Park, California, 1975-77 / by Ray J. Hoffman ; prepared in cooperation with the National Park Service