G. Amato, G. Levi. Properties of the Lattice of Observables in Logic Programming. In Moreno Falaschi, Marisa Navarro, Alberto Policriti, editors, 1997 Joint Conf. on Declarative Programming, APPIA-GULP-PRODE 97, Grado, Italy, June 16-19, 1997. pages 175-188, 1997.
Abstract is missing.