@article{HACK2000,
                author = {A.~Heaton and M.~Abo-Zaed and M.~Codish and A.~King},
                title = {A {S}imple {P}olynomial {G}roundness {A}nalysis for 
                           {L}ogic {P}rograms},
                journal = {Journal of Logic Programming},
                publisher = {Elsevier},
                volume = 45,
                number = {1-3},
                year = 2000,
                month = {September},
                pages = {143-156},
                }