1. Myers, D.G.: The American paradox: Spiritual hunger in an age of plenty. Yale University Press (2000)
2. Hall, D.R., Zhao, J.Z.: Cohabitation and Divorce in Canada: Testing the Selectivity Hypothesis. Journal of Marriage and the Family 57, 421–427 (1995)
3. Hoffman, B.: Al Qaeda, Trends in Terrorism, and Future Potentialities: An Assessment. Studies in Conflict and Terrorism 26(6), 429–442 (2003)
4. Fedor K. AAP: Financial crisis: Fears of world slump after Lehman Brothers crash, http://livenews.com.au/Articles/2008/09/16/Financial_crisis_Fears_of_world_slump_after_Lehman_Brothers_crash_
5. Mooney, C.: Our Extraordinary Tornado Year, http://www.thedailygreen.com/environmental-news/blogs/hurricanes-storms/tornado-trends-55030501