@article{GDZPPN001172875,
title = {A Theory for Nystr\"om Methods.},
journal = {Numerische Mathematik},
volume = {25},
year = {1975},
pages = {383-400},
zbl = {0307.65053},
url = {http://dml.mathdoc.fr/item/GDZPPN001172875}
}
Hairer, E.; Wanner, G. A Theory for Nyström Methods.. Numerische Mathematik, Tome 25 (1975) pp. 383-400. http://gdmltest.u-ga.fr/item/GDZPPN001172875/