- Sergey V. Gusev, Boris M. Vernikov, “Two weaker variants of congruence permutability for monoid varieties”, Semigroup Forum, 103, no. 1, 2021, 106
![https://doi.org/10.1007/s00233-021-10196-9 crossref](/refsvg/svg/crossref.svg)
- Edmond W. H. Lee, “A minimal pseudo-complex monoid”, Arch. Math., 120, no. 1, 2023, 15
![https://doi.org/10.1007/s00013-022-01797-z crossref](/refsvg/svg/crossref.svg)
- Sergey V. Gusev, “Varieties of aperiodic monoids with central idempotents whose subvariety lattice is distributive”, Monatsh Math, 201, no. 1, 2023, 79
![https://doi.org/10.1007/s00605-022-01717-x crossref](/refsvg/svg/crossref.svg)
- Edmond W. H. Lee, “On Certain Cross Varieties of Aperiodic Monoids with Commuting Idempotents”, Results. Math., 66, no. 3-4, 2014, 491
![https://doi.org/10.1007/s00025-014-0390-6 crossref](/refsvg/svg/crossref.svg)
- E. W. H. Lee, “Inherently Non-Finitely Generated Varieties of Aperiodic Monoids with Central Idempotents”, J Math Sci, 209, no. 4, 2015, 588
![https://doi.org/10.1007/s10958-015-2515-1 crossref](/refsvg/svg/crossref.svg)
- Sergey V. Gusev, Edmond W. H. Lee, Boris M. Vernikov, “The lattice of varieties of monoids”, Jpn. J. Math., 17, no. 2, 2022, 117
![https://doi.org/10.1007/s11537-022-2073-5 crossref](/refsvg/svg/crossref.svg)
- S. V. Gusev, “A new example of a limit variety of monoids”, Semigroup Forum, 101, no. 1, 2020, 102
![https://doi.org/10.1007/s00233-019-10078-1 crossref](/refsvg/svg/crossref.svg)
- Edmond W. H. Lee, Advances in the Theory of Varieties of Semigroups, 2023, 227
![https://doi.org/10.1007/978-3-031-16497-2_12 crossref](/refsvg/svg/crossref.svg)
- Sergey V. Gusev, Edmond W. H. Lee, “Varieties of monoids with complex lattices of subvarieties”, Bull. London Math. Soc., 52, no. 4, 2020, 762
![https://doi.org/10.1112/blms.12392 crossref](/refsvg/svg/crossref.svg)