1. Inequalities and separation for Schrödinger type operators in L2(Rn);Everitt;Proc. Roy. Soc. Edinburgh,1978
2. Kato, T., Perturbation theory for linear operators, Springer 1980
3. Kato, T., Holomorphic families of Dirac operators, Math. Z. to appear
4. Essential selfadjointness of Dirac operators with a strongly singular potential;Schmincke;Math. Z.,1972