References and further information:
1. Scientific and Technical Intelligence Committee - Open Source SubCom, Oct, 1991-1995 Report.pdf http://fas.org/irp/dni/osc/stic1995.pdf
2. Clark, Robert M. SCIENTIFIC AND TECHNICAL INTELLIGENCE ANALYSIS: https://www.cia.gov/library/center-for-the-study-of-intelligence/kent-csi/vol19no1/html/v19i1a06p_0001.htm
3. Studies in Intelligence (journal) Archive Index of unclassified or declassified articles: https://www.cia.gov/library/center-for-the-study-of-intelligence/kent-csi