Torrance, N., Mansoor, R., Wang, H., Gilbert, S., Macfarlane, G.J., Serpell, M., Baldacchino, A., Hales, T.G., Donnan, P., Wyper, G., Smith, B.H., Colvin, L., "Association of opioid prescribing practices with chronic pain and benzodiazepine co-prescription: a primary care data linkage study.", British journal of anaesthesia, 2018