@article{10_14708_cm_v53i1_770,
     author = {Gra\.zyna Krech},
     title = {The {Voronovskaya} type theorem for {Poisson} integrals of functions of two variables},
     journal = {Commentationes Mathematicae},
     pages = { 23--34},
     year = {2013},
     volume = {53},
     number = {1},
     doi = {10.14708/cm.v53i1.770},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v53i1.770/}
}