Get all referenced nodes in a scene

def getReferencedNodeList():

    referencedNodeList= [];

    import maya.cmds as mc;

    rnodes= mc.ls(type="reference");

    for rnode in rnodes:

        sharedAttr= rnode+".sharedReference";

        if mc.objExists(sharedAttr) and not mc.listConnections(sharedAttr,s=0,d=1):

            referencedNodeList+= mc.referenceQuery(rnode,n=True);

    return( referencedNodeList );