What are the last names of the author of the paper titled "Binders Unbound"?
create table authorship (authid varchar, paperid varchar, PRIMARY KEY (authid)); create table authors (lname varchar, authid varchar, PRIMARY KEY (lname)); create table papers (paperid varchar, title varchar, PRIMARY KEY (paperid))
select t1.lname from authors as t1 join authorship as t2 on t1.authid = t2.authid join papers as t3 on t2.paperid = t3.paperid where t3.title = "binders unbound"