1. A. Furiolli Martinolli, Su un probleme singolare di Cauchy per l'equazione(x+y)s=Ap+Bq+Cz+Df, Rend. Ist. Lombard. Sci. Lett. 100 (1967), 518–528.
2. A. Furiolli Martinolli, Su un problema singolare di Darboux per l'equazionexys=xAp+yBq+Cz+xyf 104 (1970), 680–689.
3. J. Kajiwara, Some systems of partial differential equations in the theory of soil mechanics,Mem. Fac. Sci. Kyushu Univ. Ser. A. 24 (1970), 147–230.
4. J. Kajiwara, Some systems of partial differential equations in complex domains,25 (1971), 21–143.
5. M. B. Kapilevič, A singular inhomogeneous Cauchy problem,Dokl. Akad. Nauk SSSR 175 (1967), 284–287 =Soviet Math. Dokl. 8 (1967), 844–848.