A randomised controlled trial of an intervention to increase the implementation of a healthy canteen policy in Australian primary schools: study protocol L. Wolfenden, N. Nathan, C. Williams, T. Delaney, K. Reilly, M. Freund, K. Gillham, R. Sutherland, A. Bell, L. Campbell, S. Yoong, R. Wyse, L. Janssen, S. Preece, M. Asmar, J. Wiggers 2014 / Vol. 9, pp. 1 - 8 / Implementation science