I have not been able to find a copy of this paper anywhere!
B. Knaster еt C. Kuratowski: Sur quеlquеs propriétés topologiquеs dеs fonctions dеrivéеs. Rеnd. dеl Сirc. Math. di Palеrmo, 59 (1925), З82-З86.
It is by two famous mathematicians, and is referenced here.
(1) Can you help me locate this paper?
(2) In general what are some ways you find very old mathematics papers?
(3) The original paper was written in French. What are the odds that there is a translated version available?
The paper is:
Bronisław Knaster (1893-1980) and Kazimierz [Casimir] Kuratowski (1896-1980), Sur quelques propriétés topologiques des fonctions dérivées [On some topological properties of derivative functions], Rendiconti del Circolo Matematico di Palermo (1) 49 (1925), 382-386. JFM 51.0208.01
I mentioned it in my answer to Examples of dense sets in the complex plane, although I didn't say much about it there. The paper is well known for using the graphs of pathological derivatives (e.g. derivatives having a dense set of non-continuity points) to easily obtain various pathological examples of connected sets in the plane.
Possibly someone somewhere over the years has translated the paper, but I have not encountered anyone saying that such a translation exists. (I've sometimes read in papers an author mentioning that they have translated such-and-such paper and would be willing to provide a copy to anyone requesting one, but not this particular paper.)
Finally, for older papers the Zbl and JFM look-up pages are very useful.