TY  - RPRT
TI  - Cretaceous and lower Tertiary stratigraphy of the Gurabo and El Yunque quadrangles, Puerto Rico
AU  - Victor M. Seiders
PY  - 1971
DO  - 10.3133/b1294f
UR  - https://pubs.usgs.gov/publication/b1294F
ID  - b1294F
ER  -