Gaya APA
R.Fitriati, A. et al (2007).
An Introduction to Six Sigma & Process Improvement Pengantar Six Sigma .
Jakarta:
Salemba Empat.
Gaya MLA
R.Fitriati, Afia. et al.
"An Introduction to Six Sigma & Process Improvement Pengantar Six Sigma".
Jakarta:
Salemba Empat,
2007.
Text.