TY  - RPRT
TI  - Results of the U.S. Geological Survey's Analytical Evaluation Program for standard reference samples: T-155 (trace constituents), M-148 (major constituents), N-59 (nutrient constituents), N-60 (nutrient constituents), P-31 (low ionic strength constituents), GWT-4 (ground-water trace constituents) and Hg-27 (Mercury) distributed in September 1998
AU  - Jerry W. Farrar
PY  - 1999
DO  - 10.3133/ofr9972
UR  - https://pubs.usgs.gov/publication/ofr9972
ID  - ofr9972
ER  -