Fu, Xiao Li et al., A Remark on the Boundedness of Calderón.Zygmund Operators in Nony.homogeneous Spaces, Acta mathematica Sinica. English series (Print) , 23(3), 2007, pp. 449-456
Let . be a Radon measure on Rd which may be non.doubling. The only condition satisfied by . is that .(B(x, r)) . Cr n for all x . .d, r > 0 and some fixed 0 < n . d. In this paper, the authors prove that the boundedness from H 1(.) into L 1,.(.) of a singular integral operator T with Calderón.Zygmund kernel of Hörmander type implies its L 2(.).boundedness.