M. E. Johll, D. Poister, and J. Ferguson, Statistical comparison of multiple methods for the determination of dissolved oxygen levels in natural waters, Chem. Educator 7 (2002) 146-148. J. W. Ferguson, High resolution studies of the origins of polyatomic ions in inductively coupled plasma – mass spectrometry, Dissertation (2006) Iowa State University. J. W. Ferguson and R. S. Houk, High resolution studies of the origins of polyatomic ions in inductively coupled plasma-mass spectrometry I: Identification methods and effects of neutral gas density assumptions, extraction voltage, and cone material, Spectrochim. Acta B 61 (2006) 905-915.