%0 Journal Article %A Mojdeh, Doost Ali %A Samadi, Babak %A Yero, Ismael G. %T Global defensive $k$-alliances in directed graphs: combinatorial and computational issues %J RAIRO - Operations Research - Recherche Opérationnelle %D 2020 %P 1027-1040 %V 54 %N 4 %I EDP-Sciences %U http://www.numdam.org/articles/10.1051/ro/2019049/ %R 10.1051/ro/2019049 %G en %F RO_2020__54_4_1027_0