Aziz, Firman, et al. “Klasifikasi Physical Activity Berbasis Sensor Accelorometer, Gyroscope, Dan Gravity Menggunakan Algoritma Multi-Class Ensemble GradientBoost”. JURNAL MEDIA INFORMATIKA BUDIDARMA, vol. 5, no. 4, Oct. 2021, pp. 1265-72, doi:10.30865/mib.v5i4.3222.