Systems Engineering Guide for Systems of Systems
DoD. 2008. Systems Engineering Guide for Systems of Systems, version 1.0. Washington, DC, USA: US Department of Defense (DoD). Available: http://www.acq.osd.mil/se/docs/SE-Guide-for-SoS.pdf.
This source is considered a primary reference for the Systems of Systems (SoS) article.
The full text of this source is available through the Defense Acquisition University (DAU) website.