1. AMR Research, Enterprise Resource Planning Software Report: 1997–2002, at http://www.lionhrtpub.com/orms/orms-6-99/erp.html.
2. AMR Research, at http://www.amr.com.
3. J. Bridges, at http://www.sunservermagazine.com/sun0600/erp_inet.htm.
4. M. Brown, at http://students.depaul.edu/~mbrown4/erptrends.htm.
5. E. Callaway, at http://www.managingautomation.com/BuyersGuide/bg_e_spec-complexity-grows.htm.