@article{10_4064_cm_66_2_209_217,
     author = {Jan Je{\l}owicki},
     title = {On extension of the group operation over the {\v{C}ech-Stone} compactification},
     journal = {Colloquium Mathematicum},
     pages = {209--217},
     publisher = {mathdoc},
     volume = {66},
     number = {2},
     year = {1993},
     doi = {10.4064/cm-66-2-209-217},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-66-2-209-217/}
}