@article{1183738943, author = {Gregory, John}, title = {Beth Definability in Infinitary Languages}, journal = {J. Symbolic Logic}, volume = {39}, number = {1}, year = {1974}, pages = { 22-26}, language = {en}, url = {http://dml.mathdoc.fr/item/1183738943} }
Gregory, John. Beth Definability in Infinitary Languages. J. Symbolic Logic, Tome 39 (1974) no. 1, pp. 22-26. http://gdmltest.u-ga.fr/item/1183738943/