http://wi.water.usgs.gov/models/pestplusplus/ http://pubs.usgs.gov/tm/tm7c5/ Approaches in Highly Parameterized Inversion: PEST++, a P arameter EST imation Code Optimized for Large Environmental Models By David E. Welter, 1 John E. Doherty, 2 Randall J. Hunt, 3 ...