@article{ASNSP_1972_3_26_1_67_0,
     author = {Chadam, John M.},
     title = {Asymptotics for $\square \, u = m^2 u + G (t, x, u, u_x, u_t),$, {II.} {Scattering} theory},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {67--95},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 26},
     number = {1},
     year = {1972},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1972_3_26_1_67_0/}
}