@article{10_4007_annals_2009_169_491,
     author = {Kentaro Saji and Masaaki Umehara and Kotaro Yamada},
     title = {The geometry of fronts},
     journal = {Annals of mathematics},
     pages = {491--529},
     publisher = {mathdoc},
     volume = {169},
     number = {2},
     year = {2009},
     doi = {10.4007/annals.2009.169.491},
     mrnumber = {2480610},
     zbl = {1177.53014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4007/annals.2009.169.491/}
}