Bertram Ludäscher Wolfgang May Joachim Reinert Towards a Logical Semantics for Referential Actions in SQL. 57-72 1996 FMLDO http://wwwiti.cs.uni-magdeburg.de/iti_db/IDB96-Proceedings/Ludaescher.ps.gz db/conf/fmldo/fmldo96.html#LudascherMR96