CHIA, M.; TAN, S.; TAN, A.; TAN, S. M.; LEE, B. Weighing in the Issue of Heavy Schoolbags Carried by Pupils in Primary School: 小學生書包的重量: 在新加坡的研究. Asian Journal of Physical Education & Recreation, [S. l.], v. 9, n. 1, p. 36–43, 2003. DOI: 10.24112/ajper.91133. Disponível em: https://ejournals.lib.hkbu.edu.hk/index.php/ajper/article/view/1133. Acesso em: 14 aug. 2022.