Table schema:
CREATE TABLE authorship (authid VARCHAR, paperid VARCHAR); CREATE TABLE authors (lname VARCHAR, authid VARCHAR); CREATE TABLE papers (paperid VARCHAR, title VARCHAR)

Question: What are the last names of the author of the paper titled "Binders Unbound"?
SQL: 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"