%A ?. ?. ????? %J ?????????? ??????????? "??????????? ??????, ?????? ?????????? ?? ?? ????????????" %T On the Zygmund-type estimate for a quaternion singular Cauchy integral %X We established in sufficient conditions for existence of the integralF[f] ona regular surface and proved an upper Zygmund-type estimate for its modulus ofcontinuity in terms of the modulus of continuity of the function f %D 2013 %L zu213306