Another (though, this time, rather sketchy) item in the vast
collection of publications (ab)using the existence of a chapter in
the Nikiforov's-Uvarov's 1988 monograph for re-telling us stories
about polynomial solvability of ODEs in the context of (this time,
relativistic) quantum mechanics.

MR2610110 Motavalli, Hossein; Rezaei Akbarieh, Amin Exact solutions
of the Klein-Gordon equation for the scarf-type potential via
Nikiforov-Uvarov method. Internat. J. Theoret. Phys. 49 (2010), no.
5, 979--987. 81Q05