@article{RSMUP_1995__94__99_0,
     author = {Cicognani, Massimo and Zanghirati, Luisa},
     title = {Propagation of analytic and {Gevrey} regularity for a class of semi-linear weakly hyperbolic equations},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {99--111},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {94},
     year = {1995},
     mrnumber = {1370906},
     zbl = {0848.35077},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1995__94__99_0/}
}