Parametrix for a characteristic Cauchy problem
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Serie 4, Volume 12 (1985) no. 1, p. 1-42 
@article{ASNSP_1985_4_12_1_1_0,
     author = {Bove, Antonio and Lewis, Jeff E. and Parenti, Cesare},
     title = {Parametrix for a characteristic Cauchy problem},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 12},
     number = {1},
     year = {1985},
     pages = {1-42},
     zbl = {0593.35050},
     mrnumber = {818800},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1985_4_12_1_1_0}
}

Bove, A.; Lewis, J. E.; Parenti, C. Parametrix for a characteristic Cauchy problem. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Serie 4, Volume 12 (1985) no. 1, pp. 1-42. http://www.numdam.org/item/ASNSP_1985_4_12_1_1_0/

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