Harms, T. F Summary statistics for selenium in vegetation calculated from U.S. Geological Survey data / by T.F. Harms - Denver: U.S. Geological Survey, 1995 - 31 p. : ill. ; 27 cm - U.S. Geological Survey bulletin; 2117 . Subjects--Topical Terms: SeleniumPlants--CompositionBotany--West (U.S.)Botanical chemistry