TY  - RPRT
TI  - Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in April 1994; T-129 (trace constituents), M-130 (major constituents), N-42 (nutrients), P-22 (low ionic strength), and Hg-18 (mercury)
AU  - H. Keith Long
AU  - Jerry W. Farrar
PY  - 1994
DO  - 10.3133/ofr94369
UR  - https://pubs.usgs.gov/publication/ofr94369
ID  - ofr94369
ER  -