1. Liu B (2007) Uncertainty theory, 2nd edn. Springer, Berlin
2. Liu B (2009) Some research problems in uncertain theory. J Uncertain Syst 3(1):3–10
3. Liu B (2010) Uncertain risk analysis and uncertain stability analysis. J Uncertain Syst 4(3):163–170
4. Liu B (2010) Uncertain set theory and uncertain inference rule with application to uncertain control. J Uncertain Syst 4(2):83–98
5. Liu B (2011) Uncertain logic for modeling human language. J Uncertain Syst 5(1):3–20