TY  - RPRT
TI  - Map of locations of collapse-breccia pipes in the Grand Canyon region of Arizona
AU  - Hoyt B. Sutphin
AU  - Karen J. Wenrich
PY  - 1989
DO  - 10.3133/ofr89550
UR  - https://pubs.usgs.gov/publication/ofr89550
ID  - ofr89550
ER  -