On degree resistance distance of cacti

A graph GG is called a cactus if each block of GG is either an edge or a cycle. Denote by Cact(n;t)Cact(n;t) the set of connected cacti possessing nn vertices and tt cycles. In a recent paper (Du et al., 2015), the Cact(n;t)Cact(n;t) with minimum degree resistance distance was characterized. We now determine the elements of Cact(n;t)Cact(n;t) with second-minimum and third-minimum degree resistance distances. In addition, some mistakes in Du et al. (2015) are pointed out.