Israel Journal of Mathematics · 1976 · 78 citations · 9 references
9
Michael Morley · Transactions of the American Mathematical Society · 1965 · 391 citations
Elementary properties of Abelian groups
Wanda Szmielew · Fundamenta Mathematicae · 1955 · 288 citations · Full text
John T. Baldwin, A. H. Lachlan · Journal of Symbolic Logic · 1971 · 218 citations
Ultrafilters on a countable set
David Booth · Annals of Mathematical Logic · 1970 · 168 citations