@article{ASNSP_1984_4_11_4_541_0,
     author = {Perla Menzala, Gustavo},
     title = {On perturbed wave equations with time-dependent coefficients},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {541--558},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 11},
     number = {4},
     year = {1984},
     mrnumber = {808423},
     zbl = {0592.35079},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1984_4_11_4_541_0/}
}