On the strong Roman domination number of graphs. - M. P. Álvarez-Ruiz; T. Mediavilla-Gradolph; Seyed Mahmoud Sheikholeslami; Juan Carlos Valenzuela Tripodoro; Ismael González Yero (Discret. Appl. Math., 2017)

Triple Roman domination in graphs. - Hossein Abdollahzadeh Ahangar; M. P. Álvarez-Ruiz; Mustapha Chellali; Seyed Mahmoud Sheikholeslami; Juan Carlos Valenzuela Tripodoro (Appl. Math. Comput., 2021)