@article{10_4171_dm_554,
     author = {David M\"uller},
     title = {Minimax principles, {Hardy-Dirac} inequalities, and operator cores for two and three dimensional {Coulomb-Dirac} operators},
     journal = {Documenta mathematica},
     pages = {1151--1169},
     year = {2016},
     volume = {21},
     doi = {10.4171/dm/554},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/554/}
}