@article{SMJ2_2015_41_4_a3,
     author = {K\"u\c{c}\"uk, Nisa and Duman, Oktay},
     title = {Summability {Methods} in {Weighted} {Approximation} to {Derivatives} of {Functions}},
     journal = {Serdica Mathematical Journal},
     pages = {355--368},
     publisher = {mathdoc},
     volume = {41},
     number = {4},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_2015_41_4_a3/}
}