@article{10_14708_cm_v55i1_718,
     author = {Jan-David Hardtke},
     title = {WORTH property, {Garc{\'\i}a-Falset} coefficient and {Opial} property of infinite sums},
     journal = {Commentationes Mathematicae},
     pages = { 23--44},
     publisher = {mathdoc},
     volume = {55},
     number = {1},
     year = {2015},
     doi = {10.14708/cm.v55i1.718},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v55i1.718/}
}