@article{10_4064_sm179_1_2,
     author = {Marko Huhtanen and Olavi Nevanlinna},
     title = {Approximating real linear operators},
     journal = {Studia Mathematica},
     pages = {7--25},
     publisher = {mathdoc},
     volume = {179},
     number = {1},
     year = {2007},
     doi = {10.4064/sm179-1-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm179-1-2/}
}