TY  - RPRT
TI  - MAPTOPS (version 1); a program to retrieve formation tops
AU  - C. J. Wandrey
AU  - R. C. Obuch
PY  - 1990
DO  - 10.3133/ofr89575
UR  - https://pubs.usgs.gov/publication/ofr89575
ID  - ofr89575
ER  -