\Bibitem{Ayu77} \by Sh.~A.~Ayupov \paper Homomorphisms of a class of rings and two-valued measures on Boolean algebras \jour Funktsional. Anal. i Prilozhen. \yr 1977 \vol 11 \issue 3 \pages 68--69 \mathnet{http://mi.mathnet.ru/faa2087} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=0457672} \zmath{https://zbmath.org/?q=an:0359.16023} \transl \jour Funct. Anal. Appl. \yr 1977 \vol 11 \issue 3 \pages 217--219 \crossref{https://doi.org/10.1007/BF01079467}