1. Locally Presentable and Accessible Categories;Adámek,1994
2. Quasivarieties of partial algebras — a unifying approach towards a two-value model theory for partial algebras;Andréka;Studia Scientiarum Mathematicarum Hungarica,1981
3. H. Andréka, I. Németi, Generalization of the concept of variety and quasivariety to partial algebras through category theory, Dissertationes Mathematicae (Rozprawy Matematyczne) 204 (1983) 1–51
4. Toposes, Triples and Theories;Barr,1984
5. Foundations of constructive mathematics;Beeson;Ergebnisse der Mathematik und ihrer Grenzgebiete (3),1985