@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/