Collins, Ruth and Ewing, Derek and Boggs, Bob and Taggart, Noel and Drillingcourt, Aileen and Kelly, Martin and Patterson, Diane (2009) Opiate substitution prescribing in Belfast – two year follow up study. Irish Journal of Psychological Medicine, 26, (4), pp. 183-186. https://doi.org/10.1017/s0790966700000665.