TY  - RPRT
TI  - Acid-insoluble residue/carbonate content of the Upper Cretaceous Niobrara Formation, Berthoud field, Denver basin, Colorado; a key factor for understanding natural fracturing in chalks?
AU  - R. M. Pollastro
PY  - 1991
DO  - 10.3133/ofr91330
UR  - https://pubs.usgs.gov/publication/ofr91330
ID  - ofr91330
ER  -