| Hans-Günter Meyer-Thompson | Verschiedene
GLOBAL DRUG SURVEY (GDS) 2021 KEY FINDINGS REPORT
GLOBAL DRUG SURVEY (GDS) 2021 KEY FINDINGS REPORT
WINSTOCK AR, MAIER LJ, ZHUPARRIS A, DAVIES E, PULJEVIC C, KUYPERS KPC, FERRIS JA & BARRATT MJ. (2021).
https://www.globaldrugsurvey.com/wp-content/uploads/2021/12/Report2021_global.pdf