A protocal for the extensions of the Australian Parental Supply of Alcohol Longitudinal Study (APSALS - Yuen, W.; Peacock, A.; Clare, P.; Aiken, A.; Degenhardt, L.; Boland, V.; Dixon, T.; Kypri, K.; Horwood, J.; Bruno, R.; McCambridge, J.; Wadolowski, M.; et al. (National Drug and Alcohol Research Centre, University of New South Wales, 2018)