@article{ETNA_2013__40__a8,
     author = {Gratton,  Serge and Jir\'anek,  Pavel and Vasseur,  Xavier},
     title = {Energy backward error: interpretation in numerical solution of elliptic partial differential equations and behaviour in the conjugate gradient method},
     journal = {Electronic transactions on numerical analysis},
     pages = {338--355},
     year = {2013},
     volume = {40},
     zbl = {1290.65029},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2013__40__a8/}
}