@article{EXMATH_2008_2008_1_a8,
     author = { Aiena, P. and  Biondi, M. T.},
     title = {Weyl type theorems for polaroid operators. },
     journal = {Extracta mathematicae},
     pages = {103-118},
     publisher = {mathdoc},
     volume = {23},
     number = {2},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_2008_2008_1_a8/}
}