TY  - RPRT
TI  - A semiquantitative spectrographic method for the analysis of minerals, rocks, and ores
AU  - C. L. Waring
AU  - C. S. Annell
PY  - 1951
DO  - 10.3133/tei143
UR  - https://pubs.usgs.gov/publication/tei143
ID  - tei143
ER  -