C. G. McKay. The non-separability of a certain finite extension of Heyting's propositional logic. Koninklijke Nederlandse Akademie van Wetenschappen, Proceedings, series A, vol. 71 (1968), pp. 312–315; also Indagationes mathematica«, vol. 30 (1968), pp. 312–315.
Toshio Umezawa · Journal of Symbolic Logic · 1971
C. G. McKay. The non-separability of a certain finite extension of Heyting's propositional logic. Koninklijke Nederlandse Akademie van Wetenschappen, Proceedings, series A, vol. 71 (1968), pp. 312–315; also Indagationes mathematica«, vol. 30 (1968), pp. 312–315. - Volume 36 Issue 2