@article{AIHPC_2009__26_6_2373_0,
     author = {Gu, Qilong and Li, Tatsien},
     title = {Exact {Boundary} {Controllability} for {Quasilinear} {Wave} {Equations} in a {Planar} {Tree-Like} {Network} of {Strings}},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {2373--2384},
     publisher = {Elsevier},
     volume = {26},
     number = {6},
     year = {2009},
     doi = {10.1016/j.anihpc.2009.05.002},
     mrnumber = {2569899},
     zbl = {1180.35326},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.anihpc.2009.05.002/}
}