TY - BOOK ED - National Research Council (Estados Unidos). TI - Opportunities to improve the U.S. Geological Survey National Water Quality Assessment Program SN - 0309083052 AV - TD223 O66 PY - 2002/// CY - Washington, D.C. PB - National Academy KW - National Water-Quality Assessment Program (Estados Unidos) KW - Calidad del agua KW - Estados Unidos KW - MediciĆ³n ER -