@article{BSMF_1980__108__113_0,
     author = {Piotrowski, Zbigniew},
     title = {Continuity points in $\lbrace x\rbrace \times Y$},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {113--115},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {108},
     year = {1980},
     doi = {10.24033/bsmf.1911},
     mrnumber = {82m:54007},
     zbl = {0439.54013},
     language = {en},
     url = {http://archive.numdam.org/articles/10.24033/bsmf.1911/}
}