@article{10_14708_cm_v22i1_6011,
     author = {M. R. Parameswaran},
     title = {A converse product theorem in summability},
     journal = {Commentationes Mathematicae},
     pages = { 131--134},
     year = {1980},
     volume = {22},
     number = {1},
     doi = {10.14708/cm.v22i1.6011},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v22i1.6011/}
}