title: the wasa2 object-oriented workflow management system. authors: mathias weske , gottfried vossen. venue: sigmod conference. year: 1999
title: tigukat : a uniform behavioral objectbase management system. authors: m. tamer &#214; zsu , randal peters , duane szafron , boman irani , anna lipka , adriana mu &#241; oz. venue: the vldb journal -- the international journal on very large data bases. year: 1995