If your content knowledge is sound on the Australian Constitution you understand referendums.
You are now ready to consider the role of the High Court of Australia in interpreting the Constitution.
The High Court cannot do this without the states or Commonwealth commencing an action.
When an action is commenced, either the state or the Commonwealth will lose some power under the Constitution. This is normally in the area of Residual Powers. The ruling is normally in favour of the Commonwealth.
One case that covers this aspect of interpretation of state powers under the Constitution is the Tasmanian Dam Case. The Commonwealth v Tasmania 1983 HCA