COLUMBIA, Mo. (AP) — Workers at a regional library system in central Missouri have voted to unionize. Officials said Monday that 65% of Daniel Boone Regional Library employees who voted to form a union, which will be the only active public library union in the state. The system has branches in Columbia, Fulton, Ashland and Holts Summit. The library employees covered by the union will be represented by the American Federation of State County and Municipal Employees, or AFSCME. The next step is contract negotiations, although no date has been set to begin that process.