searching a Deltagen scene tree for 'referenced' items.

Hi, does anyone know how to use Python to search a scene tree for all the referenced items? Here I am talking about the ones whose names are in italics in the scene tree.

My csb files are attached to a master scene, so when I search the entire scene using the getAllReferences() function, it gets a list of every single thing in my scene tree - presumably because they are not 'integrated' into the scene.

If I use this same function when I have actually selected one of the italicised items, then it shows me all those of the same reference (which is what are need), but I cannot understand how to search the entire scene and only find the italicised 'referenced' items.

Thanks.