Safe inhalation pipe provision (SIPP): protocol for a mixed-method evaluation of an intervention to improve health outcomes and service engagement among people who use crack cocain... oleh Magdalena Harris, Jenny Scott, Vivian Hope, Joanna Busza, Sedona Sweeney, Andrew Preston, Mat Southwell, Niamh Eastwood, Cedomir Vuckovic, Caitlynne McGaff, Ian Yoon, Louise Wilkins, Shoba Ram, Catherine Lord, Philippe Bonnet, Peter Furlong, Natasha Simpson, Holly Slater, Lucy Platt