@article{1102985564, author = {Geiger, David}, title = {Closed systems of functions and predicates.}, journal = {Pacific J. Math.}, volume = {27}, number = {3}, year = {1968}, pages = { 95-100}, language = {en}, url = {http://dml.mathdoc.fr/item/1102985564} }
Geiger, David. Closed systems of functions and predicates.. Pacific J. Math., Tome 27 (1968) no. 3, pp. 95-100. http://gdmltest.u-ga.fr/item/1102985564/