books.google.co.uk - The way people normally view a GIS is 2-dimensional, a greatly limiting form. However, as developments occur within the field, researchers and practitioners are finding ways to make a GIS 3-dimensional, and in some instances even 4-dimensional. Being able to view a GIS in more than 2 dimensions greatly...http://books.google.co.uk/books/about/Multidimensional_geographic_information.html?id=0DRv9EqSXQ8C&q=spatial+data&utm_source=gb-gplus-shareMultidimensional geographic information science
