TY  - DATA
AU  - Allison, Bruce N.
TI  - Extended affine Lie algebras and their root systems 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9781470401887 (online)
PY  - 1997///
CY  - Providence, R.I.
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0603
ER  -