Origin of Dataset ?

Hello,

I try to build in javascript a program to generate a graph of LOD.

In http://www.w3.org/TR/sparql11-service-description/
I cannot find the property  to say if the source is "media", user-generated,
government, etc...
like in this example of graph
http://en.wikipedia.org/wiki/File:Lod-datasets_2010-09-22_colored.png

Is this an oversight?

Thanks,
Karima Rafes
http://en.sparql.pro