Cocaine analytes in human hair: evaluation of concentration ratios in different cocaine sources, drug-user populations and surface-contaminated specimens.
Ropero-Miller JD, Huestis MA, Stout PR. Cocaine analytes in human hair: evaluation of concentration ratios in different cocaine sources, drug-user populations and surface-contaminated specimens. J Anal Toxicol. 2012 Jul; 36(6):390-8.