The Invariants of the Linear Partial Differential Equation of the Second Order in two Independent Variables
1912 ◽
Vol s2-10
(1)
◽
pp. 406-422
1922 ◽
Vol 41
◽
pp. 76-81
1898 ◽
Vol 62
(379-387)
◽
pp. 283-285
1868 ◽
Vol 35
(236)
◽
pp. 219-234
2021 ◽
Vol 12
(2)
◽
pp. 2810-2813
1935 ◽
Vol 064
(6)
◽
pp. 165-166