TY  - RPRT
TI  - Topographic instructions, Book 1, Part 1-A, Preface and contents
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1950
DO  - 10.3133/cir92
UR  - https://pubs.usgs.gov/publication/cir92
ID  - cir92
ER  -