title: Early graphic representations of groundwater nitrate concentrations.
authors.affiliation: Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA. bric0004@umn.edu
authors.forename: Greg
authors.initials: G
authors.lastname: Brick
authors.forename: E Calvin
authors.initials: EC
authors.lastname: Alexander
mesh_terms: D004784:Environmental Monitoring / Q000266:history* / Q000379:methods; D005308:Fertilizers / Q000032:analysis*; D060587:Groundwater / Q000737:chemistry*; D049672:History, 19th Century; D049673:History, 20th Century; D009566:Nitrates / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005308:Fertilizers; D009566:Nitrates; D014874:Water Pollutants, Chemical