CREATE TABLE authorship (authid VARCHAR(255), paperid VARCHAR(255)); CREATE TABLE authors (lname VARCHAR(255), authid VARCHAR(255)); CREATE TABLE papers (paperid VARCHAR(255), title VARCHAR(255))
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"