TY  - RPRT
TI  - Changes in sample collection and analytical techniques and effects on retrospective comparability of low-level concentrations of trace elements in ground water
AU  - T. Ivahnenko
AU  - Z. Szabo
AU  - J. Gibs
PY  - 2001
DO  - 10.1016/s0043-1354(01)00094-x
UR  - https://pubs.usgs.gov/publication/70023765
ID  - 70023765
ER  -