(Portland, OR)  --  Employees at a Portland-area Burgerville restaurant are set to begin voting on whether to unionize this weekend.  Workers at the location on 92nd and Powell are scheduled to vote on unionizing Sunday and Monday.  Meanwhile, a second Portland-area Burgerville restaurant is now also working to start a union.  Workers at the Gladstone Burgerville location have filed for a union election with the National Labor Relations Board.