TY  - JOUR
AU  - Gerd Ronning
TI  - On the Nonnegativity of XX* and its Relevance in Econometrics.
JO  - Metrika
PY  - 1985
SP  - 35
EP  - 47
VL  - 32
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MET_1985__32_175984/
ID  - MET_1985__32_175984
ER  -