@article{article2808b848,
title   = {Conditions for the existence of bound states of a dirac particle in two and three dimensions},
author = {Coutinho, Francisco Antônio Bezerra and Nogami, Y. and Parent, N P and Suzuki, A},
year = {1991},
doi = {10.1016/0375-9601(91)90538-j},
journal   = {Physics Letters a}
}