TY  - RPRT
TI  - Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in October 1994 : T-131 (trace constituents), T-133 (trace constituents), M-132 (major constituents), N-43 (nutrients), N-44 (nutrients), P-23 (low ionic strength) and Hg-19 (mercury)
AU  - H. Keith Long
AU  - Jerry W. Farrar
PY  - 1995
DO  - 10.3133/ofr95117
UR  - https://pubs.usgs.gov/publication/ofr95117
ID  - ofr95117
ER  -