Are referendum results binding?

South Sudan
Answer
Optional referendum - always
Source
Constitution (2011)http://www.sudantribune.com/IMG/pdf/The_Draft_Transitional_Constitution_of_the_ROSS2-2.pdf
Article 1933) Any matter which has been approved by the people of South Sudan in a referendum shall have authority above any legislation. It shall not be annulled save by another referendum.