TY - JOUR AU - M. Du AU - J. Delos BT - Physical Review Letters DA - Jan-04-1987 DO - 10.1103/PhysRevLett.58.1731 PY - 1987 SP - 1731 EP - 1733 T2 - Physical Review Letters TI - Effect of closed classical orbits on quantum spectra: Ionization of atoms in a magnetic field UR - http://link.aps.org/doi/10.1103/PhysRevLett.58.1731 VL - 58 SN - 0031-9007 ER -