@article{10_14712_1213_7243_2020_042,
     author = {Dr\'apal, Ale\v{s} and Jedli\v{c}ka, P\v{r}emysl and Stanovsk\'y, David},
     title = {Preface},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {409--410},
     publisher = {mathdoc},
     volume = {61},
     number = {4},
     year = {2020},
     doi = {10.14712/1213-7243.2020.042},
     mrnumber = {4230949},
     zbl = {07332718},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.14712/1213-7243.2020.042/}
}