@InProceedings{ dixoso97on, author = {J\"{u}rgen Dix and Mauricio Osorio}, title = {On {W}ell-{B}ehaved {S}emantics {S}uitable for {A}ggregation}, pages = {505}, publisher = {MIT Press}, editor = {Jan Maluszynski}, booktitle = {Logic Programming: Proceedings of the 1997 International Symposium}, year = {1997} }