Reconnaissance of the ground-water resources of the Elkhorn River Basin above Pilger, Nebraska, with a section on chemical quality of the water
John Richard Rapp
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H.M. Babcock
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W.H. Durum
Alfred E. Torrey
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Frank Albert Swenson
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Herbert A. Swenson
H.M. Babcock
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John Richard Rapp
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W.H. Durum