@article{JRAM_1987__380_152960,
     author = {S. Albeverio and F. Gesztesy},
     title = {Point interactions in two diemsions: {Basic} properties, approximations and applications to solid state physics.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {87--107},
     publisher = {mathdoc},
     volume = {380},
     year = {1987},
     zbl = {0619.35030},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1987__380_152960/}
}