@article{AIF_1999__49_6_1903_0,
     author = {Franchi, Bruno and Haj{\l}asz, Piotr and Koskela, Pekka},
     title = {Definitions of {Sobolev} classes on metric spaces},
     journal = {Annales de l'Institut Fourier},
     pages = {1903--1924},
     publisher = {Association des Annales de l{\textquoteright}institut Fourier},
     volume = {49},
     number = {6},
     year = {1999},
     doi = {10.5802/aif.1742},
     zbl = {0938.46037},
     mrnumber = {2001a:46033},
     language = {en},
     url = {https://aif.centre-mersenne.org/articles/10.5802/aif.1742/}
}