1. Indépendance conditionnelle de V=L et d’axiomes qui se rattachent au système de M. Gödel;Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences, Paris,1957
2. A note on definitions of finiteness;The Bulletin of the Research Council of Israel, Section F: Mathematics and Physics 7F,1958
3. The independence of various definitions of finiteness;Fundamenta Mathematicae,1958
4. Comparison of subtheories;Proceedings of the American Mathematical Society,1958
5. On Ackermann’s set theory;The Journal of Symbolic Logic,1959