1-P.Satyanarayana,GIS Consultant& Editorial Associate ,GIS INDIA,S.Yogendran GIS Analyst,ENC-Division IIC Technologies Private Limited ,Hyderabad,India,
2- The GIS in CCIS" by Lain Whittington,16 May 1996.
3- Developments In Uk Defence Digital Geographic Support" WHITTINGTON,I.F.G,Colonel(UK Army).