TY - BOOK AU - Kolpin, Dana W. AU - Burkart, M. R. CN - I 19.76: CY - Iowa City, Iowa : CY - Denver, Colo. : DA - 1991. ID - 200782 KW - Water quality KW - Water N1 - Distributed to depository libraries in microfiche. N1 - Shipping list no.: 92-0531-M. PB - U.S. Geological Survey ; PB - Books and Open-File Reports [distributor], PP - Iowa City, Iowa : PP - Denver, Colo. : PY - 1991. T1 - Work plan for regional reconnaissance for selected herbicides and nitrate in ground water of the mid-continent United States, 1991 TI - Work plan for regional reconnaissance for selected herbicides and nitrate in ground water of the mid-continent United States, 1991 VL - 91-59 ER -