A study on the stability of anhydroecgonine methyl ester (crack biomarker), benzoylecgonine, and cocaine in human urine . Arch Clin Psychiatry (former: Rev Psiq Clin) [Internet]. 2008 Jan. 1 [cited 2024 Jun. 29];35(supl.1):17-20. Available from: https://revistas.usp.br/acp/article/view/17176