@article{10_4064_sm_31_4_373_382,
     author = {T. Le\.za\'nski},
     title = {Sur une d\'efinition de la d\'eriv\'ee},
     journal = {Studia Mathematica},
     pages = {373--382},
     publisher = {mathdoc},
     volume = {31},
     number = {4},
     year = {1968},
     doi = {10.4064/sm-31-4-373-382},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-31-4-373-382/}
}