On countably universal Boolean algebras compact classes of models Leszek Pacholski (1973) Fundamenta Mathematicae
On models of arithmetic having non-modular substructure lattices A. Wilkie (1977) Fundamenta Mathematicae
On models with large automorphism groups. H.-D. Ebbinghaus (1971) Archiv für mathematische Logik und Grundlagenforschung
On some properties a projective model class passes on to the generated axiomatic class. Klaus Kaiser, M. Armbrust (1974) Archiv für mathematische Logik und Grundlagenforschung
On the number of countable models of stable theories Predrag Tanović (2001) Fundamenta Mathematicae We prove: Theorem. If T is a countable, complete, stable, first-order theory having an infinite set of constants with different interpretations, then I(T,ℵ₀) ≥ ℵ₀.