Final Report of the Model Based Engineering (MBE) Subcommittee
NDIA. 2011. Final Report of the Model Based Engineering (MBE) Subcommittee. Arlington, VA, USA: National Defense Industrial Association (NDIA). Available at: http://www.ndia.org/Divisions/Divisions/SystemsEngineering/Documents/Committees/M_S%20Committee/Reports/MBE_Final_Report_Document_(2011-04-22)_Marked_Final_Draft.pdf
This source is a primary reference for the What is a Model? article.
To read or download a PDF of this report, please see the NDIA website.