db/journals/dpd/FrancescoV94.html Nicoletta De Francesco Gigliola Vaglini Concurrent Behavior: A Construct to Specify the External Behavior of Objects in Object Databases. 33-58 DPD/2/P033.pdf 1994 2 Distributed and Parallel Databases 1 db/journals/dpd/dpd2.html#FrancescoV94