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