@article{1093890994, author = {Harris, James F.}, title = {Secondary extensions, meanings and non-null terms.}, journal = {Notre Dame J. Formal Logic}, volume = {14}, number = {1}, year = {1973}, pages = { 316-322}, language = {en}, url = {http://dml.mathdoc.fr/item/1093890994} }
Harris, James F. Secondary extensions, meanings and non-null terms.. Notre Dame J. Formal Logic, Tome 14 (1973) no. 1, pp. 316-322. http://gdmltest.u-ga.fr/item/1093890994/