TY  - DATA
AU  - Musson, Ian M.
AU  - Bergh, M. Van den.
TI  - Invariants under tori of rings of differential operators and related topics 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9781470402396 (online)
PY  - 1998///
CY  - Providence, R.I.
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0650
ER  -