A parenting programme to prevent abuse of adolescents in South Africa: study protocol for a randomized controlled trial by Cluver, L, Meinck, F, Shenderovich, Y, Ward, C, Herrero Romero, R, Lombard, C, Doubt, J, Steinert, J, Catanho, R, Wittesaele, C, DeStone, S, Salah, N, Mpimilashe, P, Lachman, J, Loening, H, Gardner, F, Blank, D, Nocuza, M, Lechowicz, M