\input zb-basic
\input zb-ioport
\iteman{io-port 70310108}
\itemau{Lee, Joohyung; Lifschitz, Vladimir; Palla, Ravi}
\itemti{Safe formulas in the general theory of stable models (Preliminary report)}
\itemso{ICLP, 672-676 (2008).}
\itemcc{}
\itemut{}
\itemli{doi:10.1007/978-3-540-89982-2\_55}
\end