Santos , P., M. Purificação, C. Fernandes, A. Santos, and L. Neto. “Application of the Holt Winters Model for Demand Forecasting in Additive Seasonal Series: A Case Study”. ITEGAM-JETIA, Vol. 3, no. 10, June 2017, pp. 164-8, https://itegam-jetia.org/journal/index.php/jetia/article/view/110.