TY  - DATA
AU  - Lopez, Angelo Felice
TI  - Noether-Lefschetz theory and the Picard group of projective surfaces 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9781470408619 (online)
PY  - 1991///
CY  - Providence, R.I., USA
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0438
ER  -