@article{10_4064_cm_39_1_29_33,
     author = {A. B{\l}aszczyk and U. Lorek},
     title = {A classification of {H-closed} extensions},
     journal = {Colloquium Mathematicum},
     pages = {29--33},
     publisher = {mathdoc},
     volume = {39},
     number = {1},
     year = {1978},
     doi = {10.4064/cm-39-1-29-33},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-39-1-29-33/}
}