\Bibitem{Cho41} \by George~Chogoshvili \paper \"Uber Konvergenzr\"aume \jour Sb. Math. \yr 1941 \vol 51 \issue 2 \mathnet{http://mi.mathnet.ru//eng/sm6091} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=4754} \zmath{https://zbmath.org/?q=an:0025.09601|67.0160.02}