Just say "I don't": lack of concordance between teen report and biological measures of drug use.
Delaney-Black V, Chiodo LM, Hannigan JH, Greenwald MK, Janisse J, Patterson G, Huestis MA, Ager J, Sokol RJ. Just say "I don't": lack of concordance between teen report and biological measures of drug use. Pediatrics. 2010 Nov; 126(5):887-93.