doxia - xdoc -> Multi project setup

Hello,

I have one other big question.

How can I generate a multi project setup, so that
every project uses the same css and images and builds as one website.

My Projects for example are:

+nanji-documentation
+--nanji-core
+--nanji-javafx

Where nanji-documentation should be the parent
and all other projects should be children.

Then the sites generated by mvn site should
look like this:

/ --> contents of nanji-documenation
/images/
/css/
/nanji-core/ --> contents of nanji-core
/nanji-javafx/ --> contents of nanji-javafx

Is that somehow possible?
Can you give examples of an opensource project that uses that kind of
structure?

regards,

Bernhard