@article{10_4064_cm_52_2_193_198,
     author = {Aleksander Ca{\l}ka},
     title = {Topological semigroups and {Kirk's} question},
     journal = {Colloquium Mathematicum},
     pages = {193--198},
     publisher = {mathdoc},
     volume = {52},
     number = {2},
     year = {1987},
     doi = {10.4064/cm-52-2-193-198},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-52-2-193-198/}
}