CREATE TABLE cite (cited NUMBER, citing NUMBER)
CREATE TABLE writes (aid NUMBER, pid NUMBER)
CREATE TABLE journal (homepage VARCHAR2, jid NUMBER, name VARCHAR2)
CREATE TABLE domain_author (aid NUMBER, did NUMBER)
CREATE TABLE publication (abstract VARCHAR2, cid NUMBER, citation_num NUMBER, jid NUMBER, pid NUMBER, reference_num NUMBER, title VARCHAR2, year NUMBER)
CREATE TABLE publication_keyword (kid NUMBER, pid NUMBER)
CREATE TABLE keyword (keyword VARCHAR2, kid NUMBER)
CREATE TABLE author (aid NUMBER, homepage VARCHAR2, name VARCHAR2, oid NUMBER)
CREATE TABLE domain_publication (did NUMBER, pid NUMBER)
CREATE TABLE domain (did NUMBER, name VARCHAR2)
CREATE TABLE domain_keyword (did NUMBER, kid NUMBER)
CREATE TABLE domain_conference (cid NUMBER, did NUMBER)
CREATE TABLE organization (continent VARCHAR2, homepage VARCHAR2, name VARCHAR2, oid NUMBER)
CREATE TABLE conference (cid NUMBER, homepage VARCHAR2, name VARCHAR2)
CREATE TABLE domain_journal (did NUMBER, jid NUMBER)

return me the keywords in the papers of ' University of Michigan ' .
SELECT keyword.keyword FROM author, keyword, organization, publication, publication_keyword, writes WHERE organization.name = 'University of Michigan' AND organization.oid = author.oid AND publication_keyword.kid = keyword.kid AND publication.pid = publication_keyword.pid AND writes.aid = author.aid AND writes.pid = publication.pid
SELECT "keyword"."keyword" FROM "author" JOIN "organization" ON "author"."oid" = "organization"."oid" AND "organization"."name" = 'University of Michigan' JOIN "writes" ON "author"."aid" = "writes"."aid" JOIN "publication" ON "publication"."pid" = "writes"."pid" JOIN "publication_keyword" ON "publication"."pid" = "publication_keyword"."pid" JOIN "keyword" ON "keyword"."kid" = "publication_keyword"."kid"