Issues in relation to which referendums are mandatory at the national level

Liberia
Constitutionof the Republic of Liberia
(Adoptedin January 1986)
http://www.liberianlegal.com/constitution1986.htm#_THE_LEGISLATURE
Article 91.
This Constitution may be amended whenever a proposalby either (1) two-thirds of the membership of both Houses of the Legislature or(2) a petition submitted to the Legislature, by not fewer than 10,000 citizenswhich receives the concurrence of two-thirds of the membership of both Housesof the Legislature, is ratified by two-thirds of the registered voters, votingin a referendum conducted by the Elections Commission not sooner than one yearafter the action of the Legislature.
Article91 of the Constitution provides for both mandatory referendum and citizeninitiative. When a constitutional amendment is proposed by 2/3 of both house ofthe legislation, it undergoes a mandatory referendum. Citizen initiativeprocess is triggered when a constitutional amendment is proposed by citizensthrough a petition of 10,000 or more in concurrence with 2/3 of approval ofboth Houses of the Legislature.