1. Roos et al (1991) The machine that changed the world: the story of lean production. Harper Perennial, New York, Chapter 3
2. Roos et al (1991) The machine that changed the world: the story of lean production. Harper Perennial, New York, Chapter 4
3. Spear et al (1999) Decoding the DNA of the Toyota production system. Harv Bus Rev, September 1999
4. Spear SJ (2010) The high velocity edge. McGraw-Hill, New York, Chapter 4
5. Spear SJ (2010) The high velocity edge. McGraw-Hill, New York, Chapter 5