“…The first result improving the factor 2 for 2-VCSS came from Khuller and Vishkin [9], which is a 5 3 -approximation algorithm. Garg, Vempala, and Singla [5] improved the approximation ratio to 3 2 . Cheriyan and Thurimella [1] also provides the same approximation ratio in a more general context, where they consider k-connectivity.…”