@article{10_4064_sm_131_3_271_287,
     author = {Pietro Aiena and  },
     title = {On inessential and improjective operators.},
     journal = {Studia Mathematica},
     pages = {271--287},
     publisher = {mathdoc},
     volume = {131},
     number = {3},
     year = {1998},
     doi = {10.4064/sm-131-3-271-287},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-131-3-271-287/}
}