Rais, R., Afriza, D. A., Setiawan, I., Sain, H., Fadjryani, F. and Junaidi, J. (2025) “MODELING THE IDX30 STOCK INDEX USING STEP FUNCTION INTERVENTION ANALYSIS”, BAREKENG: Jurnal Ilmu Matematika dan Terapan, 19(3), pp. 2057-2068. doi: 10.30598/barekengvol19iss3pp2057-2068.