Formal theory of overdetermined linear partial differential equations.
1970 ◽
pp. 187-194
1958 ◽
Vol 11
(1)
◽
pp. 145-151
◽
1961 ◽
Vol 14
(3)
◽
pp. 171-186
◽
1994 ◽
Vol 2
(1)
◽
2017 ◽
Vol 348
◽
pp. 385-400
◽