@article{M2AN_2000__34_1_127_0,
     author = {Barnes, Ian and Zhang, Kewei},
     title = {Instability of the eikonal equation and shape from shading},
     journal = {ESAIM: Mathematical Modelling and Numerical Analysis },
     pages = {127--138},
     publisher = {Dunod},
     address = {Paris},
     volume = {34},
     number = {1},
     year = {2000},
     mrnumber = {1735973},
     zbl = {0973.35017},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/M2AN_2000__34_1_127_0/}
}