7Montgomery, Nigel (2010)."Two-Tier ERP Suite Strategy: Considering Your Options." Gartner Group. July 28, 2012. Retrieved September 20, 2012.
8Vilpola, Inka Heidi (2014). "A method for improving ERP implementation success by the principles and process of user-centred design". Enterprise Information Systems 2(1 ): 47-76.