Eigenfunction Expansions Associated with Second‐Order Differential Equations, Part 2
1959 ◽
Vol 65
(3)
◽
pp. 151-155
1948 ◽
Vol 54
(5)
◽
pp. 485-488
1971 ◽
Vol 7
(1)
◽
pp. 1-55
◽
2011 ◽
Vol 57
(2)
◽
pp. 409-416