Just a thought. \xmlprocessbuffer and \xmlprocessfile{id}... register the tree they read under id. Is there a way to merge several id's to one tree? Hans van der Meer On 13 Apr 2016, at 16:21, Meer, Hans van der > wrote: I would like to process several input sources as one xml tree. Like this: with the sources having the structure ... ... and the code for containing: read from all sources given on -notes afterwards process all content at once Thus the content of the various source should be read into one tree to be processed, but I cannot get this done. How to amalgam this separate sources into one? Hans van der Meer