1. Hallucinogens: who, what, when, where, and why;Agar,1994
2. Drug use among 8th grade students is increasing;Edwards;Int. J. Addict.,1993
3. LSD in the USA: deja vu again?;Gold;Biol. Psychiatry,1993
4. LSD use among US High School Students;Gold;JAMA,1994
5. Generalized additive models;Hastie,1991