In this paper we introduce the notion of an unknotting index for virtual knots. We give some examples of computation by using writhe invariants, and discuss a relationship between the unknotting index and the virtual knot module. In particular, we show that for any non-negative integer $n$ there exists a virtual knot whose unknotting index is $(1,n)$.
"An Unknotting Index for Virtual Knots." Tokyo J. Math. 42 (2) 357 - 370, December 2019. https://doi.org/10.3836/tjm/1502179283