@article{1183738310, author = {Nebres, Bienvenido F.}, title = {Infinitary Formulas Preserved Under Unions of Models}, journal = {J. Symbolic Logic}, volume = {37}, number = {1}, year = {1972}, pages = { 449-465}, language = {en}, url = {http://dml.mathdoc.fr/item/1183738310} }
Nebres, Bienvenido F. Infinitary Formulas Preserved Under Unions of Models. J. Symbolic Logic, Tome 37 (1972) no. 1, pp. 449-465. http://gdmltest.u-ga.fr/item/1183738310/