Ritter A, Mellor R, Chalmers J, Sunderland M, Lancaster K. Key considerations in planning for substance use treatment: estimating treatment need and demand. J Stud Alcohol Suppl. 2019 Jan;Supp1 18:22-30. doi: 10.15288/jsads.2019.s18.22
Warttig SL, Forshaw MJ, South J, White AK. New, normative, English-sample data for the Short Form Perceived Stress Scale (PSS-4). J Health Psychol. 2013 Dec;18(12):1617-28. doi: 10.1177/1359105313508346