TY  - RPRT
TI  - Opal claystone associated with phosphate rock in northern Saudi Arabia
AU  - W.F. Outerbridge
AU  - C.R. Meissner
PY  - 1986
DO  - 10.3133/ofr86103
UR  - https://pubs.usgs.gov/publication/ofr86103
ID  - ofr86103
ER  -