Are referendum results binding?

Grenada
Constitution 39. (5) A bill to alter thissection, Schedule 1 to this Constitution or any of the provisions of thisConstitution specified in Part I of that Schedule or any of the provisions ofthe Courts Order specified in Part II of that Schedule or section 3 of the WestIndies Associated States (Appeals to Privy Council) Order 1967 shall not be submitted to the Governor forhis assent unless
[…]
c. the bill hasbeen approved on a referendum, held in accordance with such provision as may bemade in that behalf by Parliament, by not less than two-thirds of all the votesvalidly cast on that referendum.