@article{ETNA_1998__7__a11,
     author = {Beattie,  Christopher},
     title = {Harmonic {Ritz} and {Lehmann} bounds},
     journal = {Electronic transactions on numerical analysis},
     pages = {18--39},
     year = {1998},
     volume = {7},
     zbl = {0918.65027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_1998__7__a11/}
}