JOHNS, D. P.; HA, A. S. C. Methodological Problems in Direct Observation of Children’s Dietary and Activity Behaviors: 應用「直接觀察法」在學童飲食及活動行為研究的問題. Asian Journal of Physical Education & Recreation, [S. l.], v. 5, n. 1, p. 4–9, 1999. DOI: 10.24112/ajper.51214. Disponível em: https://ejournals.lib.hkbu.edu.hk/index.php/ajper/article/view/1214. Acesso em: 29 mar. 2024.