@article{AIHPC_2007__24_5_711_0,
     author = {H\'uska, Juraj and Pol\'a\v{c}ik, Peter and Safonov, Mikhail V.},
     title = {Harnack inequalities, exponential separation, and perturbations of principal {Floquet} bundles for linear parabolic equations},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {711--739},
     publisher = {Elsevier},
     volume = {24},
     number = {5},
     year = {2007},
     doi = {10.1016/j.anihpc.2006.04.006},
     mrnumber = {2348049},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.anihpc.2006.04.006/}
}