Database: scholar
Question: What paper did Michael Armstrong wrote in the 90s ?
SQL:
SELECT DISTINCT t3.year  ,  t2.paperid FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid JOIN paper AS t3 ON t2.paperid  =  t3.paperid WHERE t1.authorname LIKE "Michael Armstrong" AND t3.year LIKE "199";