1. To take hold of space: isovists and isovist fields;Bendikt;Environment and Planning B,1979
2. Perceiving architectural space: from optic arrays to isovists;Bendikt,1981
3. A spatial data model for navigation knowledge;Claramunt,1996
4. People manipulate objects (but cultivate fields): beyond the raster-vector debate in GIS;Couclelis,1992