JOHNS, David P., and Amy Sau Ching HA. 1999. “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 &Amp; Recreation 5 (1):4-9. https://doi.org/10.24112/ajper.51214.