TY  - RPRT
TI  - Sand-sized heavy-mineral distributions in the Rio Cibuco system and adjacent rivers of north-central Puerto Rico
AU  - Gretchen Luepke
AU  - L. J. Poppe
PY  - 1993
DO  - 10.3133/ofr92703
UR  - https://pubs.usgs.gov/publication/ofr92703
ID  - ofr92703
ER  -