  We present a microscopic theory for the recently observed reentrant integral
quantum Hall effect in the n=1 and n=2 Landau levels. Our energy investigations
indicate an alternating sequence of M-electron-bubble and quantum-liquid ground
states in a certain range of the partial filling factor of the n-th level.
Whereas the quantum-liquid states display the fractional quantum Hall effect,
the bubble phases are insulating, and the Hall resistance is thus quantized at
integral values of the total filling factor.
