TY  - RPRT
TI  - Optical method for determining particle sizes of coarse sediment
AU  - John R. Ritter
AU  - Edward J. Helley
PY  - 1969
DO  - 10.3133/twri05c3
UR  - https://pubs.usgs.gov/publication/twri05C3
ID  - twri05C3
ER  -