@article{10_4064_cm_43_1_151_154,
     author = {F. M. Filipczak},
     title = {On the derivative of type \ensuremath{\alpha}},
     journal = {Colloquium Mathematicum},
     pages = {151--154},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {1980},
     doi = {10.4064/cm-43-1-151-154},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-43-1-151-154/}
}