@article{1183736621, author = {Slomson, A. B.}, title = {An Undecidable Two Sorted Predicate Calculus}, journal = {J. Symbolic Logic}, volume = {34}, number = {1}, year = {1969}, pages = { 21-23}, language = {en}, url = {http://dml.mathdoc.fr/item/1183736621} }
Slomson, A. B. An Undecidable Two Sorted Predicate Calculus. J. Symbolic Logic, Tome 34 (1969) no. 1, pp. 21-23. http://gdmltest.u-ga.fr/item/1183736621/