@article{TSG_2010-2011__29__15_0,
     author = {Ghezzi, Roberta},
     title = {On {almost-Riemannian} surfaces},
     journal = {S\'eminaire de th\'eorie spectrale et g\'eom\'etrie},
     pages = {15--49},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {29},
     year = {2010-2011},
     doi = {10.5802/tsg.284},
     language = {en},
     url = {http://www.numdam.org/articles/10.5802/tsg.284/}
}