@article{EJDE_2002__2002__a2,
     author = {Langa, Jose A. and Su\'arez, Antonio},
     title = {Pullback permanence for non-autonomous partial differential equations},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2002},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2002__2002__a2/}
}