@article{1183742103, author = {Henson, C. Ward and Keisler, H. Jerome}, title = {On the Strength of Nonstandard Analysis}, journal = {J. Symbolic Logic}, volume = {51}, number = {1}, year = {1986}, pages = { 377-386}, language = {en}, url = {http://dml.mathdoc.fr/item/1183742103} }
Henson, C. Ward; Keisler, H. Jerome. On the Strength of Nonstandard Analysis. J. Symbolic Logic, Tome 51 (1986) no. 1, pp. 377-386. http://gdmltest.u-ga.fr/item/1183742103/