Oberwittler, Dietrich Criminology, Max Planck Institute for Foreign and International Criminal Law, Max Planck Society;
https://doi.org/10.1016/j.jcrimjus.2010.07.002 (Any fulltext)
Svensson, R., & Oberwittler, D. (2010). It's not the time they spend, it's what they do: the interaction between delinquent friends and unstructured routine activity on delinquency. Findings from two countries. Journal of Criminal Justice, 38(5), 1006-1014. doi:10.1016/j.jcrimjus.2010.07.002.