@article{10_4064_sm168_3_5,
     author = {Valentino Magnani},
     title = {Differentiability from the representation formula and
 the {Sobolev{\textendash}Poincar\'e} inequality},
     journal = {Studia Mathematica},
     pages = {251--272},
     publisher = {mathdoc},
     volume = {168},
     number = {3},
     year = {2005},
     doi = {10.4064/sm168-3-5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm168-3-5/}
}