@article{AFST_1999_6_8_1_53_0,
     author = {Moreira Cavalcanti, Marcelo},
     title = {Exact controllability of the wave equation with {Neumann} boundary condition and time-dependent coefficients},
     journal = {Annales de la Facult\'e des sciences de Toulouse : Math\'ematiques},
     pages = {53--89},
     publisher = {Universit\'e Paul Sabatier. Facult\'e des sciences},
     address = {Toulouse},
     volume = {Ser. 6, 8},
     number = {1},
     year = {1999},
     mrnumber = {1721574},
     zbl = {1002.93023},
     language = {en},
     url = {http://www.numdam.org/item/AFST_1999_6_8_1_53_0/}
}