@article{10_4064_fm_75_2_169_174,
     author = {W{\l}adys{\l}aw Wilczy\'nski},
     title = {On the family of sets of approximate limit numbers},
     journal = {Fundamenta Mathematicae},
     pages = {169--174},
     publisher = {mathdoc},
     volume = {75},
     number = {2},
     year = {1972},
     doi = {10.4064/fm-75-2-169-174},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-75-2-169-174/}
}