@article{ARM_1999_35_1_a3,
     author = {Cavalcanti, M. M.},
     title = {Exact controllability of the wave equation with mixed boundary condition and time-dependent coefficients},
     journal = {Archivum mathematicum},
     pages = {29--57},
     year = {1999},
     volume = {35},
     number = {1},
     mrnumber = {1684521},
     zbl = {1046.35013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1999_35_1_a3/}
}