Who decides on the final form of the ballot text?

Forexample of a law regulating referendums, see:

The Referendum Law for the Approval of the DraftConstitution of the Republic of the Union of Myanmar (Enacted on 26th February, 2008)

http://www.ibiblio.org/obl/docs4/Referendum_Law-2008-02-26.pdf

Article 397 of the Constitution states that the “Pyidaungsu Hluttaw shall enact the necessary laws on matters relating to ‘Election’ and on matters relating to ‘Recall’”. No such law governing referendum is found.

For the 2008 Constitutional Referendum, a law (see source) was enacted to regulate and govern the conduct of the referendum. This law specified that the referendum commission had the responsibility of ‘prescribing the forms, seals, ballot papers and advance ballot papers to be used by the Commission and Sub-commissions for holding referendum’.