TY  - RPRT
TI  - Felsic-mafic ratios and silica saturation ratios; their rationale and use as petrographic and petrologic indicators
AU  - E. J. Young
PY  - 1989
DO  - 10.3133/ofr89651
UR  - https://pubs.usgs.gov/publication/ofr89651
ID  - ofr89651
ER  -