@article{oai:soar-ir.repo.nii.ac.jp:00011738,
 author = {Odake,  Satoru and Sasaki,  Ryu},
 issue = {23},
 journal = {JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL},
 month = {Jun},
 note = {We address the problem of rational extensions of six examples of shape-invariant potentials having finitely many discrete eigenstates. The overshoot eigenfunctions are proposed as candidates unique in this group for the virtual state wavefunctions, which are an essential ingredient for multi-indexed and iso-spectral extensions of these potentials. They have exactly the same form as the eigenfunctions but their degrees are much higher than n(max) so that their energies are lower than the groundstate energy., Article, JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL. 46(23):235205 (2013)},
 title = {Extensions of solvable potentials with finitely many discrete eigenstates},
 volume = {46},
 year = {2013}
}