Naresh Kumar, H. and Venkatakrishnan, Y.B. 2020. Trees with vertex-edge Roman Domination number twice the domination number minus one. Proyecciones (Antofagasta, On line). 39, 6 (Nov. 2020), 1381-1392. DOI:https://doi.org/10.22199/issn.0717-6279-2020-06-0084.