The theorem on the basis property of eigenfunctions of second order differential operators with involution
2020 ◽
Vol 12
(3)
◽
pp. 15-21
Keyword(s):
1999 ◽
Vol 59
(1)
◽
pp. 227-251
1983 ◽
Vol 8
(6)
◽
pp. 643-665
◽
2016 ◽
Vol 52
(12)
◽
pp. 1563-1574
◽
Keyword(s):
Keyword(s):