@article{AM2_1977__16_136692,
     author = {A. Bacopoulos and R.V.M. Zahar},
     title = {An error anlysis for absolute and relative approximation. {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {190--193},
     publisher = {mathdoc},
     volume = {16},
     year = {1977},
     url = {http://geodesic.mathdoc.fr/item/AM2_1977__16_136692/}
}