Pyzdek, T., & Keller, P. A. (2018). The six sigma handbook (Fifth edition.). McGraw-Hill Education.
Lua i Stíl Chicago (17ú heag.)Pyzdek, Thomas, agus Paul A. Keller. The Six Sigma Handbook. Fifth edition. New York: McGraw-Hill Education, 2018.
Lua MLA (9ú heag.)Pyzdek, Thomas, agus Paul A. Keller. The Six Sigma Handbook. Fifth edition. McGraw-Hill Education, 2018.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.