Silly thing
Reading one article about 6S noticed that authors referenced one single article (actually written by Warwick Uni people) on a number of different ways : (Antony and Banuelas, 2002) and Coronado et al. (2002). The references look like this:
Antony, J., Banuelas, R. (2002), "Critical success factors for the successful implementation of six-sigma projects in organizations", The TQM Magazine, Vol. 14 No.2, pp.92–9.
Coronado, R., Banuelas, R., Antony, J. (2002), "Critical success factors for the successful implementation of six sigma projects in organisations", The TQM Magazine, Vol. 14 No.2, pp.92–9.
As you may see in the second version the article is written by 3 (!) people, one of whose is a completely imaginary person!