Strong equality of Roman and perfect Roman Domination in trees Zehui Shao, Saeed Kosari, Hadi Rahbani, Mehdi Sharifzadeh and Seyed Mahmoud Sheikholeslami RAIRO-Oper. Res., 56 1 (2022) 381-394 Published online: 10 February 2022 DOI: 10.1051/ro/2022005