\Bibitem{Wag38} \by V.~Wagner \paper \"Uber Berwaldsche R\"aume \jour Sb. Math. \yr 1938 \vol 45 \issue 3 \mathnet{http://mi.mathnet.ru//eng/sm5728} \zmath{https://zbmath.org/?q=an:0019.27701|64.0759.04}