Hartanto, A., Ong, N. C. H., Ng, W. Q., & Majeed, N. M. (2020). The effect of state gratitude on cognitive flexibility: A within-subject experimental approach. Brain Sciences, 10(7), 413. https://doi.org/10.3390/brainsci10070413
SMU Office of Research and Tech Transfer. (2020, August 16). Understanding the psychological aspects of the COVID-19 pandemic. https://research.smu.edu.sg/news/2020/aug/16/understanding-psychological-aspects-covid-19-pandemic.