1. Lake, R., Burggraf, D.S., et. al. (2005) GML: Foundation for the Geo-Web, London, UK: Wiley & Sons.
2. Lake, R., Cox, S., et. al. (2004) OpenGIS® Geography Markup Language Implementation Specification, OGC 03-105r1, Version 3.1.1.
3. Vretanos, P.A. (2002) OpenGIS® Web Feature Service Implementation Specification, OGC 01-065r1,Version 1.0.0.