More links and websites
This section of the Elections New Zealand website provides information on referendums that have been held in New Zealand.
More suggestions and sources
Atkinson, Neill. Adventures in democracy: a history of the vote in New Zealand. Dunedin: University of Otago Press, 2003.
Christoffel, Paul. ‘Prohibition and the Myth of 1919.’ New Zealand Journal of History 42, no. 2 (2008): 154–175.
Church, Stephen. ‘Crime and punishment: the referenda to reform the criminal justice system and reduce the size of Parliament.’ In Left turn: the New Zealand general election of 1999, edited by Jonathan Boston and others, pp. 184–198. Wellington: Victoria University Press, 2000.