\Bibitem{Sko65} \by L.~A.~Skornyakov \paper On Cohn rings \jour Algebra i Logika. Sem. \yr 1965 \vol 4 \issue 3 \pages 5--30 \mathnet{http://mi.mathnet.ru/al1024} \mathscinet{https://mathscinet.ams.org/mathscinet-getitem?mr=0193105}