Aharonov-Bohm effect and the mass of the photon
David G. Boulware and S. Deser
Phys. Rev. Lett. 63, 2319 (1989) - Published 20 November, 1989
Antiadiabatic theorem for crossing levels
F. E. Low
Phys. Rev. Lett. 63, 2322 (1989) - Published 20 November, 1989