Galoyan, L.N. “ON CONVERGENCE IN NORM OF SOME IRREGULAR $L_1[0, 1]$ LINEAR MEANS OF WALSH–FOURIER SERIES”. Proceedings of the YSU A: Physical and Mathematical Sciences, vol. 46, no. 1 (227), Mar. 2012, pp. 10-15, doi:10.46991/PYSU:A/2012.46.1.010.