TY  - RPRT
TI  - Methodological issues in drug usage surveys: anonymity, recency, and frequency.
AU  - M J Luetgert
AU  - A H Armstrong
PY  - 1973
DO  - 10.3109/10826087309057494
UR  - https://pubmed.ncbi.nlm.nih.gov/4761647/
ID  - 4761647
ER  -