On the partial sums of Vilenkin-Fourier series
  The main aim of this paper is to investigate weighted maximal operators of partial sums of Vilenkin-Fourier series. We also use our results to prove approximation and strong convergence theorems on the martingale Hardy spaces $H_{p},$ when $0<p\leq 1.$ 
George Tephnadze
math.CA math.FA