The famous characterization of countably categorical theories state that such a theory is equivalent with a theory with a finite amount of $n-$types for each $n$, a theory where all models are atomic, a theory which has a saturated elementarily prime model etc. This theorem is cited, in both Chang/Kieslers Model theory, Hodges Model theory and Rothmalers Introduction to model theory, to be a result from 1959 by Engeler, Ryll-Nardzewski and Svenonius all independently. The paper which is cited as Engelers part is the following paper:
Engeler E., A characterization of theories with isomorphic denumerable models, Notices of the American Mathematical Society 6 (1959) 161.
However, when I search on MathSciNet or Zentralblath math for this article nothing appears. Often articles (especially obscure old soviet articles) can not be accessed but are still indexed by these sites, yet this paper (which even belongs to the AMS thus should at least be on MathSciNet) does not appear. When I google the paper, I only find more books and papers which cite it. When I look at Engelers webpage he does not mention it as one of his papers (and he seems to have a quite extensive list).
My question is why? Why can't I find this paper? Why isn't it mentioned anywhere except in references? Where can I find this paper?