@article{10_4064_cm_45_2_221_225,
     author = {Witold Bula},
     title = {On continua having three types of open subsets},
     journal = {Colloquium Mathematicum},
     pages = {221--225},
     publisher = {mathdoc},
     volume = {45},
     number = {2},
     year = {1981},
     doi = {10.4064/cm-45-2-221-225},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-45-2-221-225/}
}