Varieties of abelian quasigroups Jaroslav Ježek, Tomáš Kepka (1977) Czechoslovak Mathematical Journal
Varieties of idempotent groupoids with small clones J. Gałuszka (1999) Colloquium Mathematicae We give an equational description of all idempotent groupoids with at most three essentially n-ary term operations.
Varieties of quasigroups determined by short strictly balanced identities Jaroslav Ježek, Tomáš Kepka (1979) Czechoslovak Mathematical Journal