Nasution, N., D. R. Sitompul, and W. Walhidayat. “Application of Sales Forecasting Using The Least Square Method in Web-Based Information Systems”. JURNAL TEKNOLOGI DAN OPEN SOURCE, Vol. 6, no. 1, Jan. 2023, pp. 11 -22, doi:10.36378/jtos.v6i1.2580.