Jan Scheffczyk Uwe M. Borghoff Peter Rödig Lothar Schmitz Consistent document engineering: formalizing type-safe consistency rules for heterogeneous repositories. 140-149 2003 conf/doceng/2003 ACM Symposium on Document Engineering http://doi.acm.org/10.1145/958220.958246 db/conf/doceng/doceng2003.html#ScheffczykBRS03