APA-viite (7. p.)

Hayler, R., & Nichols, M. (2005). What is six sigma process management? (First edition.). McGraw-Hill Education.

Chicago-viite (17. p.)

Hayler, Rowland, ja Michael Nichols. What Is Six Sigma Process Management? First edition. New York: McGraw-Hill Education, 2005.

MLA-viite (9. p.)

Hayler, Rowland, ja Michael Nichols. What Is Six Sigma Process Management? First edition. McGraw-Hill Education, 2005.