Preventing overdose using information and data from the environment (PROVIDENT): Protocol for a randomised, population-based, community intervention trial
B. D. L. Marshall, N. Alexander-Scott, J. L. Yedinak, B. Hallowell, W. C. Goedel, B. Allen, R. C. Schell, M. S. Krieger, C. Pratty, J. Ahern, D. B. Neill, M. Cerda