TY  - RPRT
TI  - Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in September 1996 : T-143 (trace constituents), T-145 (trace constituents), M-140 (major constituents), N-51 (nutrient constituents), N-52 (nutrient constituents), P-27 (low ionic strength constituents), and Hg-23 (mercury)
AU  - J.W. Farrar
AU  - H.K. Long
PY  - 1997
DO  - 10.3133/ofr9720
UR  - https://pubs.usgs.gov/publication/ofr9720
ID  - ofr9720
ER  -