Maurizio Rafanelli Fernando Ferri VIDDEL: an object-oriented VIsual Data DEfinition Language for statistical data. 18-28 SSDBM92/P018.pdf 1992 SSDBM db/conf/ssdbm/ssdbm92.html#RafanelliF92 conf/ssdbm/92 db/conf/ssdbm/RafanelliF92.html