TY  - RPRT
TI  - An approach toward a combined scheme for the petrographic classification of fly ash: Revision and clarification
AU  - J.C. Hower
AU  - I. Suarez-Ruiz
AU  - Maria Mastalerz
PY  - 2005
DO  - 10.1021/ef0498061
UR  - https://pubs.usgs.gov/publication/70029078
ID  - 70029078
ER  -