1. Checkland, P.B. (1981), System Thinking, System Practice, Wiley, Chichester.
2. Ding, W. (2006), “Knowledge complexity review”, Journal of Guangxi Normal University, Vol. 42 No. 1, pp. 113‐7.
3. Fang, F.K. (2004), “Economic complexity and correlative issues”, Science & Technology Review, No. 8, pp. 134‐8.
4. Gu, J.F. and Gao, F. (1998), “To see Wuli‐Shili‐Renli systems approach from the view of management science”, Systems Engineering – Theory & Practice, No. 8, pp. 167‐71.
5. Gu, J.F. and Tang, X.J. (2006), Wuli‐Sili‐Renli System Approach: Theory and Application, Shanghai Education Press, Shanghai.