Department of Computer Engineering and Mathematics;
Rovira i Virgili University;
Av.Pai'sos Catalans 26;
43007 Tarragona;
Spain;
Department of Economy;
Quantitative Methods and Economic History;
Pablo de Olavide University;
Carretera de Utrera Kin.1;
41013-Sevilla;
Spain;
Department of Computer Engineering and Mathematics;
Rovira i Virgili University;
Av.Paisos Catalans 26;
43007 Tarragona;
Spain;
Faculty of Mathematics;
Autonomous University of Guerrero;
Carlos E.Adame 5;
Co1.La Garita;
Acapulco;
Guerrero;
Mexico;
Defensive alliances; dominating sets; domination; isoperimetric number;