@article{EJDE_2011__2011__a91,
     author = {Mingarelli, Angelo B.},
     title = {A note on {Sturm-Liouville} problems whose spectrum is the set of prime numbers},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2011},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2011__2011__a91/}
}