@article{AM2_1978__18_136772,
     author = {R.V.M. Zahar and Bacopoulos.A.},
     title = {An error analysis for absolute and relative approximation.},
     journal = {Aequationes mathematicae},
     pages = {158--177},
     publisher = {mathdoc},
     volume = {18},
     year = {1978},
     zbl = {0383.41021},
     url = {http://geodesic.mathdoc.fr/item/AM2_1978__18_136772/}
}