Montero F, et al. "Potency-Enhancing Synthetics in the Drug Overdose Epidemic: Xylazine ('Tranq'), Fentanyl, Methamphetamine, and the Displacement of Heroin in Philadelphia and Tijuana". Journal of Illicit Economies and Development 2022; 4(2): 204-222. DOI:10.31389/jied.122Je zde použita šablona {{DOI}} označená jako k „pouze dočasnému použití“.