\Bibitem{Dav31} \by B.~Davison \paper Inversion of the Unicity-Theorem \jour Sb. Math. \yr 1931 \vol 38 \issue 1 \mathnet{http://mi.mathnet.ru//eng/sm6864} \zmath{https://zbmath.org/?q=an:0003.31103|57.0348.01}