Sacha Berger Emmanuel Coquery Wlodzimierz Drabent Artur Wilk Descriptive Typing Rules for Xcerpt. 85-100 2005 conf/ppswr/2005 PPSWR http://dx.doi.org/10.1007/11552222_9 db/conf/ppswr/ppswr2005.html#BergerCDW05