TY  - JOUR
AU  - Ewa Ligocka
TI  - How to prove Fefferman's theorem without use of differential geometry
JO  - Annales Polonici Mathematici
PY  - 1981
SP  - 117
EP  - 130
VL  - 39
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/ap-39-1-117-130/
DO  - 10.4064/ap-39-1-117-130
LA  - en
ID  - 10_4064_ap_39_1_117_130
ER  -