Publications
Every positive integer is the Frobenius number of a numerical semigroup with three generators. Math. Scand.. 2004;94:5-12.Edit
Presentations for subsemigroups of finitely generated commutative semigroups. Israel J. Math.. 1999;113:269-283.Edit
On numerical semigroups with high embedding dimension. J. Algebra. 1998;203:567-578.Edit
Every numerical semigroup is one half of a symmetric numerical semigroup. Proc. Amer. Math. Soc.. 2008;136:475-477 (electronic).Edit
The oversemigroups of a numerical semigroup. Semigroup Forum. 2003;67:145-158.Edit
Irreducible ideals of finitely generated commutative monoids. J. Algebra. 2001;238:328-344.Edit
Pseudo-symmetric numerical semigroups with three generators. J. Algebra. 2005;291:46-54.Edit
On free affine semigroups. Semigroup Forum. 1999;58:367-385.Edit
Fundamental gaps in numerical semigroups. J. Pure Appl. Algebra. 2004;189:301-313.Edit
Systems of inequalities and numerical semigroups. J. London Math. Soc. (2). 2002;65:611-623.Edit
On full affine semigroups. J. Pure Appl. Algebra. 2000;149:295-303.Edit
On Cohen-Macaulay subsemigroups of $\bold N^2$. Comm. Algebra. 1998;26:2543-2558.Edit
Numerical semigroups having a Toms decomposition. Canad. Math. Bull.. 2008;51:134-139.Edit
Numerical semigroups with embedding dimension three. Arch. Math. (Basel). 2004;83:488-496.Edit
Proportionally modular Diophantine inequalities. J. Number Theory. 2003;103:281-294.Edit
Commutative ideal extensions of abelian groups. Semigroup Forum. 2001;62:311-316.Edit
Modular Diophantine inequalities and numerical semigroups. Pacific J. Math.. 2005;218:379-398.Edit
Finitely generated commutative monoids Nova Science Publishers, Inc., Commack, NY 1999.Edit
Arf numerical semigroups. J. Algebra. 2004;276:3-12.Edit
Presentations of finitely generated submonoids of finitely generated commutative monoids. Internat. J. Algebra Comput.. 2002;12:659-670.Edit
Reduced commutative monoids with two Archimedean components. Boll. Unione Mat. Ital. Sez. B Artic. Ric. Mat. (8). 2000;3:471-484.Edit
On Cohen-Macaulay and Gorenstein simplicial affine semigroups. Proc. Edinburgh Math. Soc. (2). 1998;41:517-537.Edit
The set of solutions of a proportionally modular Diophantine inequality. J. Number Theory. 2008;128:453-467.Edit
Numerical semigroups. Vol 20 Springer, New York 2009.Edit