Applied Mathematics and Computation, vol.153, no.1, pp.155-163, 2004 (SCI-Expanded)
We obtain sufficient conditions for the series ∑an, which is absolutely summable of order k by a weighted mean method, to be such that ∑εnan is absolutely summable of order k by a triangular matrix. As corollaries we obtain a number of inclusion theorems. © 2003 Elsevier Inc. All rights reserved.