Fourth order boundary value problems with finite spectrum

@article{Ao2014FourthOB,
  title={Fourth order boundary value problems with finite spectrum},
  author={Ji-jun Ao and Fang-zhen Bo and Jiong Sun},
  journal={Appl. Math. Comput.},
  year={2014},
  volume={244},
  pages={952-958}
}
Abstract For every positive integer m we construct a class of regular self-adjoint and non-self-adjoint fourth order boundary value problems with at most 3 m + 1 eigenvalues, counting multiplicity. 

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