Sh:13

Bib entry
@article{Sh:13,
 author = {Shelah, Saharon},
 title = {{Every two elementarily equivalent models have isomorphic ultrapowers}},
 journal = {Israel J. Math.},
 fjournal = {Israel Journal of Mathematics},
 volume = {10},
 year = {1971},
 pages = {224--233},
 issn = {0021-2172},
 doi = {10.1007/BF02771574},
 mrclass = {02H99},
 mrnumber = {0297554},
 mrreviewer = {J. L. Bell},
 doi = {10.1007/BF02771574}
}