, 1974, The meaning of "space" in Kant, in L. White Beck (ed.), Kant's theory of knowledge, Dordrecht, Springer, pp. 87-94.
, 1972, The meaning of "space" in Kant, in L. White Beck (ed.), Proceedings of the Third international Kant congress, Dordrecht, Springer, pp. 393-400.
, 1969a, A new theory of the physical existent as a compound actuality, in , Sektionen V-IX, Freiburg-Basel-Wien, Herder, pp. 305-313.