\Bibitem{Kud53} \by L.~D.~Kudryavtsev \paper On summability of Jacobians \jour Sb. Math. \yr 1953 \vol 75 \issue 2 \mathnet{http://mi.mathnet.ru/eng/sm5356} \mathscinet{https://mathscinet.ams.org/mathscinet-getitem?mr=57965} \zmath{https://zbmath.org/?q=an:0053.03304}