@article{SF_1996__52_3_135458,
     author = {M.J. Huang},
     title = {On the ergodic limits for unitary periodic propagators.},
     journal = {Semigroup forum},
     pages = {325--334},
     year = {1996},
     volume = {52},
     number = {3},
     zbl = {0853.47003},
     url = {http://geodesic.mathdoc.fr/item/SF_1996__52_3_135458/}
}