Gusev, Sergey V. ; Vernikov, Boris M. Two weaker variants of congruence permutability for monoid varieties Semigroup Forum 103, No. 1, 106-152 (2021) : [review]Henno, JaakzbMATH Open2022 / 1 p. https://zbmath.org/1484.20100 On endomorphisms of groups of orders 37-47Leibak, Alar; Puusemp, PeeterProceedings of the Estonian Academy of Sciences2017 / p. 137-150 https://doi.org/10.3176/proc.2017.2.04 http://www.ester.ee/record=b2355998*est Stepanova, A.A. ; Chekanov, S.G. Congruence-permutable S-actsHenno, JaakzbMATH Open2022 / 1 p https://zbmath.org/1485.20143