DBMS:

• GRASS 5.0/5.3: There are PostgreSQL and ODBC interfaces available
• GRASS 6: full DBMS integration

Erosion modeling:

• Modeling topographic potential for erosion and deposition using GIS (Postscript, 19 pages)
• Terrain analysis and erosion modeling (online)
• Interacting fields approach for evolving spatial phenomena: application to erosion simulation for optimized land use (Postscript, 15 pages). Online version with links.
• ANSWERS: Introduction from Purdue University (Postscript, 7 pages)
• Excerpt from ANSWERS user's manual (Postscript, 7 pages)
• The AGNPS-page
• AGNPS documentation collection

Hydrologic Modeling:

• SWAT - GRASS - Interface (Soil and water assessment tool) (online)
• References for r.water.fea - Finite element simulation for surface runoff etc. (Postscript)

Image processing:

• Image processing tutorial (Postscript, 47 pages)

Landscape structure analysis:

• r.le GRASS 5 (2001): Quantitative analysis of landscape structures (PDF)
• r.le GRASS 4.x: Quantitative analysis of landscape structures (online and Postscript )

Raster analysis:

• Short command reference (Postscript, 4 pages)
• Performing Boolean Operations in GRASS 4.0: r.combine tutorial (Postscript, 15 pages)
• GRASS 4.0 Inference engine: r.infer (Postscript, 18 pages)
• r.mapcalc: An algebra for GIS and image processing (PDF, 22 pages)
• Performing map calculations on GRASS data: r.mapcalc program tutorial (PDF, 13 pages)
• r.le 2.2: Quantitative analysis of landscape structures (online and Postscript )
• F-tools: Floodplane analysis (online)
• r.watershed Tutorial and r.watershed hints (Text)
• r.water.fea tutorials (PS)

Sites analysis:

• s.sample tutorial
• Calculating autocorrelation with GRASS (Postscript, 7 pages)

Terrain modeling/Geomorphology/
Soil Science:

• Modeling topographic potential for erosion and deposition using GIS (Postscript, 19 pages)
• Topography, soil horizons, and erosion/deposition (online)
• Surface modeling (online)
• Terrain analysis and erosion modeling (online)
• nviz - tool for viewing data surfaces in three dimensions for GRASS (online)
• Interpolation by regularized splines with tension - I. Theory (s.surf.tps) (Postscript, 24 pages)
• Interpolation by regularized splines with tension - II. Application to terrain modeling and surface geometry analysis (s.surf.tps) (Postscript, 18 pages)
• Modeling topographic potential for erosion and deposition using GIS (Postscript, 19 pages)
• Toward a Fission Track Tectonic Image of Australia: Model based interpolation in the Snowy Mountains using a GIS (online)
• GRASS 4.0 Tutorial: DTED and DEM Elevation Data Extraction (Postscript, 13 pages)

Vector management:

• Short command reference (Postscript, 2 pages)
• Short introduction from user's guide (Postscript, 7 pages)
• GRASS 4.0 map digitizing manual: v.digit (PDF, 53 pages)
• Deutsche Übersetzung des GRASS 4.0 map digitizing manual: v.digit (online)
• SDTS support and sample data
• GRASS Tutorial: DLG-3 data extraction (Postscript, 6 pages)
• Exporting DXF - Information from info.grass.user (Postscript, 2 pages)
• DXF and GRASS 
• And one more: DXF and GRASS
• Calculating autocorrelation with GRASS (Postscript, 7 pages)
• SDTS user guide (Postscript)

Visualization:

• GRASS 5: GRID3D: Multidimensional interpolation and visualization in GRASS GIS (online)
• Multidimensional interpolation and visualization in GRASS GIS (online)
• Interpolation and visualization from 3D scattered data using GRASS GIS (online)
• Multidimensional dynamic cartography (Postscript, 7 pages)
• Implementation of a parallel high-performance visualization technique in GRASS GIS (Research article)