TY  - RPRT
TI  - Characterization of humic acid fractions by C-13 nuclear magnetic resonance spectroscopy
AU  - Robert L. Wershaw
AU  - Kevin A. Thorn
AU  - D.J. Pinckney
PY  - 1988
DO  - 10.1080/09593338809384538
UR  - https://pubs.usgs.gov/publication/70014847
ID  - 70014847
ER  -