摘要：In this paper, we are concerned with the inverse spectral problems for differential pencils defined on $[0,\pi ]$ with an interior discontinuity. We prove that two potential functions are determined uniquely by one spectrum and a set of values of eigenfunctions at some interior point $b\in (0,\pi )$ in the situation of $b=\pi /2$ and $b\neq \pi /2$ . For the latter, we need the knowledge of a part of the second spectrum.
