TY  - DATA
AU  - Persson, Ulf
TI  - On degenerations of algebraic surfaces 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9781470401030 (online)
PY  - 1977///
CY  - Providence
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0189
ER  -