@article{AIF_2007__57_4_1023_0,
     author = {Mustapha, Sami and Vigneron, Fran\c{c}ois},
     title = {Construction of {Sobolev} spaces of fractional order with sub-riemannian vector fields},
     journal = {Annales de l'Institut Fourier},
     pages = {1023--1049},
     publisher = {Association des Annales de l{\textquoteright}institut Fourier},
     volume = {57},
     number = {4},
     year = {2007},
     doi = {10.5802/aif.2285},
     mrnumber = {2339325},
     zbl = {1143.46021},
     language = {en},
     url = {https://aif.centre-mersenne.org/articles/10.5802/aif.2285/}
}