Jones, Peter R. Varieties of left restriction semigroups : [review]Zentralblatt MATH2018 / [1] p https://zbmath.org/?q=06963384

Shaprynskiǐ, V. Yu.; Skokov, D. V.; Vernikov, B. M. Cancellable elements of the lattices of varieties of semigroups and epigroups : [review]Henno, JaakZentralblatt MATH2020 / 1 p https://zbmath.org/?q=an:07098151