\(\int{\text{erfc\ }\left(\text{A\ ξ}\right)\text{\ ξ}^{-n}d\xi=-\frac{\text{erfc\ }\left(\text{G\ ξ}\right)}{\left(n-1\right)\ \xi^{n-1}}-\frac{2\ G}{\left(n-1\right)\ \sqrt{\pi}}}\ \int\frac{e^{-G^{2}\text{\ ξ}^{2}}}{\xi^{n-1}}\text{dξ}\) (6)