Nordhaus–Gaddum type results for connected and total domination Rana Khoeilar, Hossein Karami, Mustapha Chellali, Seyed Mahmoud Sheikholeslami and Lutz Volkmann RAIRO-Oper. Res., 55 (2021) S853-S862 Published online: 02 March 2021 DOI: 10.1051/ro/2020025