Nicolas, I think that you didn't understand my problem but Silke did. Thanks Silke, I'll give it a try. Does the fetch function use "AND" or "OR" operator on nodes in the nodes array in your example. For my problem, I need "AND"...
--
Nothing is impossible. Not if you can imagine it!
Marko,
yes, it is "AND".
The result is an array of your "News" and "Science" objects. That way you can also sort all objects from these two nodes in one list.