Devi Dwi Rianti, Emilia, et al. “THE HEAVY LOAD OF THE BACKPACK ON THE SHOULDER POSITION AT THE AGE OF 12-15 YEARS AT SMPN 56 SURABAYA”. BIOMA : Jurnal Ilmiah Biologi, vol. 13, no. 1, Apr. 2024, pp. 29-35, doi:10.26877/bioma.v13i1.375.