1. Transport.govt.nz Travel Patterns: Household Travel 2014 http://www.transport.govt.nz/ourwork/tmif/travelpatterns/tp007/
2. Head injuries to bicyclists and the New Zealand bicycle helmet law;Scuffham;Accid. Anal. Prev.,2000
3. Cycling and Helmet Safety 2016 https://education.nzta.govt.nz/__data/assets/pdf_file/0013/25231/cycling-and-helmet-safety.pdf
4. Transit New Zealand New Zealand Supplement to the Austroads Guide to Traffic Engineering Practice Part 14: Bicycles 2008 http://www.nzta.govt.nz/assets/resources/nz-supplement-austroads-gtep-part-14-bicycles/docs/nz-supplement-austroads-gtep-part-14-bicycles.pdf