@article {MR0822451,
    AUTHOR = {Michael, E.},
     TITLE = {A note on completely metrizable spaces},
   JOURNAL = {Proc. Amer. Math. Soc.},
  FJOURNAL = {Proceedings of the American Mathematical Society},
    VOLUME = {96},
      YEAR = {1986},
    NUMBER = {3},
     PAGES = {513--522},
      ISSN = {0002-9939,1088-6826},
   MRCLASS = {54E50 (54C10)},
  MRNUMBER = {822451},
MRREVIEWER = {H.\ H.\ Wicke},
       DOI = {10.2307/2046606},
       URL = {https://doi.org/10.2307/2046606},
}



@article {MR0126251,
    AUTHOR = {Frol\'{\i}k, Zden\v{e}k},
     TITLE = {Invariance of {$G\sb{\delta }$}-spaces under mappings},
   JOURNAL = {Czechoslovak Math. J.},
  FJOURNAL = {Czechoslovak Mathematical Journal},
    VOLUME = {11(86)},
      YEAR = {1961},
     PAGES = {258--261},
      ISSN = {0011-4642},
   MRCLASS = {54.60},
  MRNUMBER = {126251},
MRREVIEWER = {J.\ R.\ Isbell},
note={http://dml.cz/dmlcz/100459}, 
}




@article {MR0124870,
    AUTHOR = {Frol\'{\i}k, Zden\v{e}k},
     TITLE = {Baire spaces and some generalizations of complete metric
              spaces},
   JOURNAL = {Czechoslovak Math. J.},
  FJOURNAL = {Czechoslovak Mathematical Journal},
    VOLUME = {11(86)},
      YEAR = {1961},
     PAGES = {237--248},
      ISSN = {0011-4642},
   MRCLASS = {54.20},
  MRNUMBER = {124870},
MRREVIEWER = {J.\ R.\ Isbell},
note={ http://dml.cz/dmlcz/100457}, 
}


@article {MR0116305,
    AUTHOR = {Frol\'{\i}k, Zden\v{e}k},
     TITLE = {Generalizations of the {$G\sb{\delta }$}-property of complete
              metric spaces},
   JOURNAL = {Czechoslovak Math. J.},
  FJOURNAL = {Czechoslovak Mathematical Journal},
    VOLUME = {10(85)},
      YEAR = {1960},
     PAGES = {359--379},
      ISSN = {0011-4642},
   MRCLASS = {54.00},
  MRNUMBER = {116305},
MRREVIEWER = {J.\ R.\ Isbell},
note= {http://dml.cz/dmlcz/100420}, 
}