Title Nordhaus–Gaddum bounds for connected and total Roman domination Type of Research Article Keywords Nordhaus–Gaddum bounds for connected and total Roman domination Abstract Nordhaus–Gaddum bounds for connected and total Roman domination Researchers Rana Khoeilar (First Researcher)، hossein karami (Second Researcher)، Mustapha Chellali (Third Researcher)، Seyed Mahmoud Sheikholeslami Kavkani (Fourth Researcher)، Lutz Volkmann (Fifth Researcher)