@article{Straccia09,
Author = {Umberto Straccia and Manuel Ojeda-Aciego and Carlos V. Dam{\'a}sio},
Journal = {SIAM Journal on Computing},
Number = {5},
Pages = {1881-1911},
Title = {On Fixed-points of Multi-valued Functions on Complete Lattices and their Application to Generalized Logic Programs}, Volume = {8},
Year = {2009}}