@article{GDZPPN002211890,
title = {Lagrange's Four Squares Theorem with almost prime variables.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {450},
year = {1994},
pages = {59-96},
zbl = {0809.11060},
url = {http://dml.mathdoc.fr/item/GDZPPN002211890}
}
Brüdern, Jörg; Fouvry, Etienne. Lagrange's Four Squares Theorem with almost prime variables.. Journal für die reine und angewandte Mathematik, Tome 450 (1994) pp. 59-96. http://gdmltest.u-ga.fr/item/GDZPPN002211890/