Second-order differential-operator equations with discrete spectrum on the whole axis
Keyword(s):
2006 ◽
Vol 6
(3)
◽
pp. 269-290
◽
Keyword(s):
1986 ◽
Vol 83
◽
pp. 29-38
◽
Basis property of a system of eigenfunctions of a second-order differential operator with involution
2019 ◽
Vol 29
(2)
◽
pp. 183-196