Key points are not available for this paper at this time.
In general the potential function q (x) in a Sturm–Liouville problem is uniquely determined by two spectra. It is shown here that if q (x) is prescribed over the interval (1{2, 1}), then a single spectrum suffices to determine q (x) on the interval (0, 1{2}).
Hochstadt et al. (Thu,) studied this question.