@article{AULFM_2013_18_a3,
     author = {Witu{\l}a, Roman and Hetmaniok, Edyta and S{\l}ota, Damian},
     title = {Families of {Increasing} {Sequences} {Possessing} the {Harmonic} {Series} {Property}},
     journal = {Acta Universitatis Lodziensis. Folia Mathematica},
     publisher = {mathdoc},
     volume = {18},
     year = {2013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AULFM_2013_18_a3/}
}