@article{10_4064_fm189_3_4,
     author = {Todor Tsankov},
     title = {Compactifications of $\mathbb{N}$ 
 and {Polishable} 
subgroups of $S_{\infty}$},
     journal = {Fundamenta Mathematicae},
     pages = {269--284},
     publisher = {mathdoc},
     volume = {189},
     number = {3},
     year = {2006},
     doi = {10.4064/fm189-3-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm189-3-4/}
}