TY  - JOUR
AU  - Hoffmann, Detlev
TI  - Pythagoras numbers of fields
JO  - Journal of the American Mathematical Society
PY  - 1999
SP  - 839
EP  - 848
VL  - 12
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-99-00301-X/
DO  - 10.1090/S0894-0347-99-00301-X
ID  - 10_1090_S0894_0347_99_00301_X
ER  -