Loredana Afanasiev Torsten Grust Maarten Marx Jan Rittinger Jens Teubner Recursion in XQuery: put your distributivity safety belt on. 345-356 2009 EDBT http://doi.acm.org/10.1145/1516360.1516401 conf/edbt/2009 db/conf/edbt/edbt2009.html#AfanasievGMRT09