@article{EJDE_2002__2002__a102,
     author = {Langa,  Jose A. and Su\'arez,  Antonio},
     title = {Pullback permanence for non-autonomous partial differential equations},
     journal = {Electronic journal of differential equations},
     year = {2002},
     volume = {2002},
     zbl = {1010.35014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2002__2002__a102/}
}