N. R. . Barreiros and H. E. N. da Silva, “Methodological procedure for applying DMAIC model of six sigma methodology in a beverage company: a case study”, Int J Innov Educ Res, vol. 8, no. 4, pp. 51–73, Apr. 2020, doi: 10.31686/ijier.vol8.iss4.2258.