00713naa a2200181 a 450000100080000000500110000800800410001910000170006024500820007726000090015952001790016865300210034765300200036865300260038865300200041470000200043477300770045410021392019-04-03       1977    bl uuuu     u00u1 u    #d1 aSMITH, J. M.  aDatabase abstractionsbaggregation and generalization.h[electronic resource]  c1977  aIntroduction; Generalization abstractions; The generic structure; Modeling with the generic structure; Relational invariants; Concluding remarks; Acknowledgments; references.  aData abstraction  aDesign de dados  aIntegrity constraints  aModelo de dados1 aSMITH, D. C. P.  tACM Transactions on Database Systemsgv. 2, n. 2, p. 106-133, June 1977.