TY  - RPRT
TI  - Modifications of two palynological processing techniques; ultrasonic processing and early-stage sieving
AU  - T.P. Sheehan
PY  - 1992
DO  - 10.3133/ofr92564
UR  - https://pubs.usgs.gov/publication/ofr92564
ID  - ofr92564
ER  -