Trees with equal Roman {2}-domination number and independent Roman {2}-domination number Pu Wu, Zepeng Li, Zehui Shao and Seyed Mahmoud Sheikholeslami RAIRO-Oper. Res., 53 2 (2019) 389-400 Published online: 06 March 2019 DOI: 10.1051/ro/2018116