issue 2 publication date 2018-12-01

• Classification of rings with toroidal annihilating-ideal graph
• On the harmonic index of bicyclic graphs
• Complexity and approximation ratio of semitotal domination in graphs
• Some results on a supergraph of the comaximal ideal graph of a commutative ring
• Lower bounds on the signed (total) $k$-domination number
• Leap Zagreb indices of trees and unicyclic graphs