@article{MV_1971_23_1_a12,
     author = {S. N. Lal},
     title = {On the absolute summability factors of infinite series},
     journal = {Matemati\v{c}ki vesnik},
     pages = {109 },
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {1971},
     url = {http://geodesic.mathdoc.fr/item/MV_1971_23_1_a12/}
}