Database: scholar
Question: how many papers does Mirella Lapata cite
SQL:
SELECT DISTINCT COUNT ( t3.citedpaperid ) FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid JOIN cite AS t3 ON t2.paperid  =  t3.citingpaperid WHERE t1.authorname  =  "Mirella Lapata";