1. Delgado, M., García-Sánchez, P.A., Morais, J.: “Numericalsgps”: a $\mathsf{GAP}$ [12] package on numerical semigroups. http://www.gap-system.org/Packages/numericalsgps.html
2. Gilmer, R.: Commutative semigroup rings. The University of Chicago Press, Chicago (1984)
3. Moreno, M.A., Nicola, J., Pardo, E.: Irreducible numerical semigroups having Toms decomposition. Commun. Algebra 35, 501–513 (2007)
4. Rosales, J.C., García-Sánchez, P.A.: Finitely Generated Commutative Monoids. Nova Science, New York (1999)
5. Rosales, J.C., García-Sánchez, P.A.: Numerical semigroups having a Toms decomposition. Can. Math. Bull. 51(1), 134–139 (2008)