Database: scholar
Question: I want the co-authors of papers on Machine Translation Output with Philipp Koehn
SQL:
SELECT DISTINCT t1.authorid FROM paperkeyphrase AS t6 JOIN keyphrase AS t3 ON t6.keyphraseid  =  t3.keyphraseid JOIN writes AS t4 ON t4.paperid  =  t6.paperid JOIN writes AS t5 ON t5.paperid  =  t4.paperid JOIN author AS t1 ON t5.authorid  =  t1.authorid JOIN author AS t2 ON t4.authorid  =  t2.authorid WHERE t2.authorname  =  "Philipp Koehn" AND t3.keyphrasename  =  "Machine Translation Output";