Spenley, P. (1995). Step change total quality: Achieving world class business performance (2nd ed.). Chapman & Hall.
Lua i Stíl Chicago (17ú heag.)Spenley, Paul. Step Change Total Quality: Achieving World Class Business Performance. 2nd ed. London: Chapman & Hall, 1995.
Lua MLA (9ú heag.)Spenley, Paul. Step Change Total Quality: Achieving World Class Business Performance. 2nd ed. Chapman & Hall, 1995.
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