1. Ahmad A. M. and Aliyu A. A. (2012). The Need for Landscape Information Modelling (LIM) in Landscape Architecture. Paper presented at the Digital Landscape Architecture Conference Bernburg Germany.
2. Aouad G. Wu S. and Lee A. (2011). Architecture Engineering and Construction. Florence KY USA: Routledge.
3. Autodesk. (2005). Parametric Building Modeling: BIM's Foundation. (Accesses Sep 18 2014)
4. buildingSMART International. (2013a). IfcGeographicElement type for phisycal feature of 3D terrain. Sep 27 2014 from http://jira.buildingsmart.org/browse/IFR-891
5. buildingSMART International. (2013b). Industry Foundation Classes Release 4 (IFC4). Retrieved Sep 21 2014 from http://www.buildingsmarttech.org/ifc/IFC4/final/html/index.htm