@article {MR0293605,
    AUTHOR = {Mr\'{o}wka, S.},
     TITLE = {Continuous functions on countable subspaces},
   JOURNAL = {Portugal. Math.},
  FJOURNAL = {Portugaliae Mathematica},
    VOLUME = {29},
      YEAR = {1970},
     PAGES = {177--180},
      ISSN = {0032-5155,1662-2758},
   MRCLASS = {54C20},
  MRNUMBER = {293605},
MRREVIEWER = {J.\ W.\ Rogers, Jr.},
}

@article {MR4431927,
    AUTHOR = {Gutev, Valentin},
     TITLE = {Simultaneous extension of continuous and uniformly continuous
              functions},
   JOURNAL = {Studia Math.},
  FJOURNAL = {Studia Mathematica},
    VOLUME = {265},
      YEAR = {2022},
    NUMBER = {2},
     PAGES = {121--139},
      ISSN = {0039-3223,1730-6337},
   MRCLASS = {54C20 (26A16 46B40 54C30 54C35 54E40)},
  MRNUMBER = {4431927},
MRREVIEWER = {Mihai\ Turinici},
       DOI = {10.4064/sm201019-22-6},
       URL = {https://doi.org/10.4064/sm201019-22-6},
}