Equivariant Picard groups and Laurent polynomials

Let $G$ be a finite group. For $G$-ring $A,$ let ${\rm Pic}^{\it G}({\it A})$ denote the equivariant Picard group of $A.$ We show that if $A$ is type algebra over field $k$ then contracted in sense Bass with contraction $H_{et}^{1}(G; Spec(A), \mathbb{Z}).$ This gives natural decomposition A[t, t^{-1}]}).$