@article{JEMS_2009_11_5_a5,
     author = {Andrea Cianchi and Nicola Fusco and Francesco Maggi and Aldo Pratelli},
     title = {The sharp {Sobolev} inequality in quantitative form},
     journal = {Journal of the European Mathematical Society},
     pages = {1105--1139},
     publisher = {mathdoc},
     volume = {11},
     number = {5},
     year = {2009},
     doi = {10.4171/jems/176},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/176/}
}