TY  - JOUR
AU  - Graham Hall
TI  - Some general, algebraic remarks on tensor classification, the group $O(2,2)$ and sectional curvature in 4-dimensional manifolds of neutral signature
JO  - Colloquium Mathematicum
PY  - 2017
SP  - 63
EP  - 86
VL  - 150
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/cm7140s-3-2017/
DO  - 10.4064/cm7140s-3-2017
LA  - en
ID  - 10_4064_cm7140s_3_2017
ER  -