@article{CMUC_2011_52_2_a10,
     author = {Tkachenko, M.},
     title = {Cellularity and the index  of narrowness in topological groups},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {309--315},
     year = {2011},
     volume = {52},
     number = {2},
     mrnumber = {2849053},
     zbl = {1240.54109},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_2011_52_2_a10/}
}