References
- http://itu.int
- http://www.iso.org
- http://www.iec.ch
- https://www.ieee.org
- https://www.ietf.org
- http://openmobilealliance.org
- https://www.w3.org
- http://www.opengeospatial.org
- http://www.isotc211.org
- http://www.buildingsmart.org
- http://www.web3d.org
- https://www.oasis-open.org
- http://www.sig3d.org
- http://www.citygmlwiki.org/index.php/CityGML-ADEs