TY  - RPRT
TI  - Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in May 1995 : T-135 (trace constituents), M-134 (major constituents), N-45 (nutrients), N-46 (nutrients), P-24 (low ionic strength), Hg-20 (mercury), and SED-5 (bed material)
AU  - H.K. Long
AU  - J.W. Farrar
PY  - 1995
DO  - 10.3133/ofr95395
UR  - https://pubs.usgs.gov/publication/ofr95395
ID  - ofr95395
ER  -