Horsburgh, S, Malik, Moona, Noris, P, Harrison-Woolrych, M, Tordoff, J, Becket, Gordon, Herbison, P, Parkin, L and Reith, D (2009) Prescribing and dispensing data sources in New Zealand: their usage and future directions. Otago University Press. ISBN 978-0-473-15463-9