Ramadhani, I., A. Damayanti, and E. Winarko. “Hybrid Extreme Learning Machine Dan Firefly Algorithm Untuk Meramalkan Nilai Tukar Rupiah Terhadap Dolar”. Contemporary Mathematics and Applications (ConMathA), vol. 3, no. 2, Oct. 2021, pp. 112-29, doi:10.20473/conmatha.v3i2.29802.