共 8 条
[1]
Gel0fand I.M., 1955, Amer. Math. Soc. Transl. (2), V1, P253
[2]
Gelfand I.M., 1951, IZV AKAD NAUK SSSR M, V2, P253
[7]
POSCHEL J, 1987, INVERSE SPECTRAL THE
[8]
TITCHMARSH EC, 1946, EIGENFUNCTION EXPA 1