The Database Group at University of Hagen (FernUniversitaet).

http://doi.acm.org/10.1145/202660.202672 Gunter Schlageter Thomas Berkel Eberhard Heuel Silke Mittrach Andreas Scherer Wolfgang Wilkes The Database Group at University of Hagen (FernUniversitaet). 79-84 sigmodR/24-1/P079.pdf 1995 24 SIGMOD Record 1 db/journals/sigmod/sigmod24.html#SchlageterBHMSW95