@incollection{Gott98a,
   author = {G.~Gottlob AND M.~Schrefl},
   booktitle = {{Semantics in Databases}},
   editor = {B.~Thalheim AND L.~Libkin},
   pages = {92--113},
   publisher = {Springer Verlag},
   series = {Lecture Notes in Computer Science, LNCS Vol.\ 1358},
   title = {{The Evolving Algebra Semantics of Class and Role Hierarchies}},
   year = {1998}
}
back