On Transitive Models for Fragments of Set Theory. - V. Wiktor Marek; M. Srebrny (Bull. Acad. Pol. des Sci. Ser. Sci. Math. Astron. Phys., 1973)

No minimal transitive model of Z-. - V. Wiktor Marek; M. Srebrny (Math. Log. Q., 1975)