Residents of southern Sudan vote Sunday in a long-awaited referendum on whether to split from the north and form their own country. Analysts expect the oil-rich south will choose independence in the Jan. 9 referendum, which lasts a week, possibly…

The timing of the Jan. 9 vote on whether Sudan will become two countries is "set in stone," despite some major unresolved issues from distribution of oil wealth to citizenship rights, State Department officials said Thursday.