Detra, D. E., & Cooley, E. F. (1988). A modification of the U.S. Geological Survey one-sixth order semiquantitative spectrographic method for the analysis of geologic materials that improves limits of determination of some volatile to moderately volatile elements. Department of the Interior, U.S. Geological Survey.
Chicago Style (17th ed.) CitationDetra, D. E., and Elmo F. Cooley. A Modification of the U.S. Geological Survey One-sixth Order Semiquantitative Spectrographic Method for the Analysis of Geologic Materials That Improves Limits of Determination of Some Volatile to Moderately Volatile Elements. [Reston, Virginia]: Department of the Interior, U.S. Geological Survey, 1988.
MLA (9th ed.) CitationDetra, D. E., and Elmo F. Cooley. A Modification of the U.S. Geological Survey One-sixth Order Semiquantitative Spectrographic Method for the Analysis of Geologic Materials That Improves Limits of Determination of Some Volatile to Moderately Volatile Elements. Department of the Interior, U.S. Geological Survey, 1988.