@article{AFM_2015_40_1_a18,
     author = {Radoslaw Szwedek},
     title = {Interpolation of approximation numbers between {Hilbert} spaces},
     journal = {Annales Fennici Mathematici},
     pages = {343--360},
     publisher = {mathdoc},
     volume = {40},
     number = {1},
     year = {2015},
     doi = {10.5186/aasfm.2015.4014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.2015.4014/}
}