Hydrology of the Great Plains aquifer system in Nebraska, Colorado, Kansas, and adjacent areas /
Helgesen, John O.
Hydrology of the Great Plains aquifer system in Nebraska, Colorado, Kansas, and adjacent areas / by John O. Helgesen, Robert B. Leonard and Ronald J. Wolf - Washington : U.S. Government Printing Office, 1993 - 79 p. : ill. ; 27 cm. - U.S. Geological Survey professional paper ; 1414-E .
Hydrology of the Great Plains aquifer system in Nebraska, Colorado, Kansas, and adjacent areas / by John O. Helgesen, Robert B. Leonard and Ronald J. Wolf - Washington : U.S. Government Printing Office, 1993 - 79 p. : ill. ; 27 cm. - U.S. Geological Survey professional paper ; 1414-E .