Beginning September 2, the American Geological Institute (AGI) is offering deep discounts of up to 90% off on various titles for purchases made by October 1, 2011. All Global GIS CD-ROMs and DVDs are marked down to an incredible $10.00. Minerals: Foundations of Society and the Glossary of Hydrology (normally $40.00) will each be available for $10.00. The Glossary of Geology is on sale for $69.00 (regularly $99.95). Shipping is extra, while supplies last.