Parkes, Tessa, Matheson, Catriona, Carver, Hannah, Budd, John, Liddell, Dave, Wallace, Jason, Pauly, Bernie, Fotopoulou, Maria, Burley, Adam, Anderson, Isobel, MacLennan, Graeme, Foster, Rebecca, "Supporting Harm Reduction through Peer Support (SHARPS): testing the feasibility and acceptability of a peer-delivered, relational intervention for people with problem substance use who are homeless, to improve health outcomes, quality of life and social functioning and reduce harms: study protocol", Pilot and Feasibility Studies, 2019