An apology from Frischer et al.
Frischer
M
M
Goldberg
D
D
Bloor
M
M
Green
S
S
McKeganey
N
N
D003430:Cross-Sectional Studies; D006801:Humans; D015994:Incidence; D011643:Publishing / Q000592:standards*; D012606:Scotland / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D014505:Urban Population / Q000706:statistics & numerical data*