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Varieties of finite categories Alex Weiss, Denis Therien (1986) RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Varieties of groupoids associated with involuted restrictive bisemigroups of binary relations. D.A. Bredikhin (1992) Semigroup forum
Varieties of groupoids determined by short linear identities Jaroslav Ježek, Tomáš Kepka (1989) Czechoslovak Mathematical Journal
Varieties of left distributive semigroups Tomáš Kepka (1984) Acta Universitatis Carolinae. Mathematica et Physica
Varieties of operator semigroups representing partitions. R. Padmanabhan, H. Lakser, B. Wolk (1995) Semigroup forum
Varieties of quasigroups determined by short strictly balanced identities Jaroslav Ježek, Tomáš Kepka (1979) Czechoslovak Mathematical Journal