\Bibitem{Ers83} \by Yu.~L.~Ershov \paper Regularly $r$-closed fields \jour Algebra Logika \yr 1983 \vol 22 \issue 4 \pages 382--402 \mathnet{http://mi.mathnet.ru/al1820} \mathscinet{https://mathscinet.ams.org/mathscinet-getitem?mr=758668}