@article{AIHPA_1989__51_3_231_0,
     author = {Grigore, D. R. and Nenciu, G. and Purice, R.},
     title = {On the nonrelativistic limit of the {Dirac} hamiltonian},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {231--263},
     publisher = {Gauthier-Villars},
     volume = {51},
     number = {3},
     year = {1989},
     mrnumber = {1034588},
     zbl = {0705.35115},
     language = {en},
     url = {http://www.numdam.org/item/AIHPA_1989__51_3_231_0/}
}