@article{10_4171_ggd_450,
     author = {Michal Doucha},
     title = {Metric topological groups: their metric approximation and metric ultraproducts},
     journal = {Groups, geometry, and dynamics},
     pages = {615--636},
     year = {2018},
     volume = {12},
     number = {2},
     doi = {10.4171/ggd/450},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/450/}
}