Legal provisions for mandatory referendums at national level

Kazakhstan
Constitution
http://www.kazakhstan.orexca.com/kazakhstan_constitution.shtml#2
Article 91. Amendments and additions to the Constitution of the Republic of Kazakhstan may be introduced only by an all-nation referendum held by the decision of the President of the Republic made on his own initiative, at the recommendation of Parliament or the Government. The draft of amendments and additions to the Constitution shall not be submitted to an all-nation referendum if the President decides to pass it to the consideration of Parliament. [...]
There are no provisions for mandatory referendums in the legislation of the country.