@article{10_4064_cm_8_1_81_82,
     author = {R. Boas},
     title = {Differentiability of jump functions},
     journal = {Colloquium Mathematicum},
     pages = {81--82},
     publisher = {mathdoc},
     volume = {8},
     number = {1},
     year = {1961},
     doi = {10.4064/cm-8-1-81-82},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-8-1-81-82/}
}