@article{MS2_1980__46_166694,
     author = {Robert Magnus},
     title = {A splitting lemma for non-reflexive {Banach} spaces.},
     journal = {Mathematica Scandinavica},
     pages = {118--128},
     year = {1980},
     volume = {46},
     zbl = {0436.58005},
     url = {http://geodesic.mathdoc.fr/item/MS2_1980__46_166694/}
}