“…For the case R 00 (λ) = 1, R 01 (λ) = -h in (1.2) and R 10 (λ) = 1, R 11 (λ) = H in (1.3), the operator U(q, U 0 , U 1 ) turns to a classical Sturm-Liouville problem L(q, h, H). Inverse spectral problems and inverse nodal problems of L(q, h, H) have been well studied, the readers can refer to [2,[10][11][12][13][14][15][16][17][18][19][20][21] and the references therein.…”