@article{articleee480a1c,
title   = {The Dirac Hamiltonian with a superstrong Coulomb field},
author = {Voronov, B L and Gitman, Dmitri Maximovitch and Tyutin, I V},
year = {2007},
doi = {10.1007/s11232-007-0004-5},
journal   = {Theoretical and Mathematical Physics}
}