@article{MOMA_1989__107_3_178420,
     author = {J\"org Br\"udern},
     title = {Sums of {Four} {Cubes.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {179--188},
     publisher = {mathdoc},
     volume = {107},
     number = {3},
     year = {1989},
     zbl = {0679.10038},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1989__107_3_178420/}
}