Bogstrand, S.T., Middelkoop, G. and Christophersen, A.S. 2011. Trends in amphetamine and benzodiazepine use among drivers arrested for drug impaired driving in Norway 2000-2009. Norsk Epidemiologi. 21, 1 (Dec. 2011). DOI:https://doi.org/10.5324/nje.v21i1.1427.