@techreport{CGS06a,
author = {R. Caballero and Y. Garc\'ia-Ruiz and F. S\'aenz-P\'erez},
institution = {Facultad de {I}nform\'atica, {U}niversidad {C}omplutense de {M}adrid},
note = {https://www.fdi.ucm.es/profesor/rafa/papers/TR0206.pdf},
number = {02/06},
title = {A Set Oriented Calculus for Logic Programming},
year = {2006}
}