G. Hasenjaeger. On definability and derivability. Mathematical interpretation of formal systems, Studies in logic and the foundations of mathematics, North-Holland Publishing Company, Amsterdam1955, pp. 15–25.
Thomas Frayne · Journal of Symbolic Logic · 1959
G. Hasenjaeger. On definability and derivability. Mathematical interpretation of formal systems, Studies in logic and the foundations of mathematics, North-Holland Publishing Company, Amsterdam1955, pp. 15–25. - Volume 24 Issue 2