@article{JEMS_2006_8_2_a8,
     author = {Jean Dolbeault and Maria J. Esteban and \'Eric S\'er\'e},
     title = {General results on the eigenvalues of operators with gaps, arising from both ends of the gaps. {Application} to {Dirac} operators},
     journal = {Journal of the European Mathematical Society},
     pages = {243--251},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {2006},
     doi = {10.4171/jems/50},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/50/}
}