Side Effects of Water Resources Management, Report of an IHP-III Working Group, Publ. No. 172, 1988, $40. Sediment Budgets, Proc. of the Porto Alegre Symposium, December 1988, Publ. No. 174, 1988, provisional price $60. Consequences of Spatial Variability in Aquifer Properties and Data Limitations for Groundwater Modeling Practice, Report of an IAHSIICGW Working Group, Publ. No. 175, 1988, $45. Karst Hydrogeology and Karst Environment Protection, Proceedings of the 21st Congress of the International Association of Hydrogeologists (sponsored by IAHS).