Restrained {2}-domination in graphs Kazhal Haghparast, Jafar Amjadi, Mustapha Chellali and Seyed Mahmoud Sheikholeslami RAIRO-Oper. Res., 57 5 (2023) 2393-2410 Published online: 19 September 2023 DOI: 10.1051/ro/2023120