\Bibitem{Fin58} \by S.~P.~Finikov \paper Voss surfaces in $E_4$ \jour Dokl. Akad. Nauk SSSR \yr 1958 \vol 120 \issue 6 \pages 1214--1216 \mathnet{http://mi.mathnet.ru/dan23189} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=0105127} \zmath{https://zbmath.org/?q=an:0178.55303}