1. Managing strategic surprise by response to weak signals;Ansoff;California Management Review,1975
2. Viestintä-Tuloksen tekijä;Åberg,1989
3. Intelligence power in peace and war;Herman,1996
4. Surprise attack, lessons for defense planning;Betts,1982
5. Early warning indicators of corporate failure, a critical review of previous research and further empirical evidence;Morris,1997