A DOI provides a permanent link to the document.
It is preferable to a URL because they are very accessible and easy to find online.
You don't need to include database information at all, because when appended to http://dx.doi.org.libproxy.nps.edu/ the link will lead to the source.
Sanico, G., & Kakinaka, M. (2008). Terrorism and deterrence policy with transnational support. Defence & Peace Economics, 19, 153 –167. doi:10.1080/10242690701505419
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