Systematic review on intentional non-medical fentanyl use among people who use drugs oleh Vivian W. L. Tsang, James S.H. Wong, James S.H. Wong, Jean N. Westenberg, Noor H. Ramadhan, Hasti Fadakar, Mohammadali Nikoo, Mohammadali Nikoo, Victor W. Li, Victor W. Li, Nick Mathew, Nick Mathew, Pouya Azar, Pouya Azar, Kerry L. Jang, Reinhard M. Krausz