Application of ANN-GARCH on Volatility Analysis of Forecasting the Level of First Level Hospitalization Cost Claims (RITP) BPJS Health. JV [Internet]. 2025 Oct. 31 [cited 2025 Dec. 31];8(3):347–362. Available from: https://journal.universitasbumigora.ac.id/Varian/article/view/5422