1. Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50(2), 179–211.
2. Anderson, J. C., & Gerbing, D. W. J. P. b. (1988). Structural equation modeling in practice: A review and recommended two-step approach. 103(3), 411.
3. AVA. (2019). AVA Annual Report 2018–2019. Retrieved from Singapore: https://www.sfa.gov.sg/files/annualreport/AR2018-19/
4. Barry, M., Cashore, B., Clay, J., Fernandez, M., Lebel, L., Lyon, T., Whelan, T. (2012). Toward sustainability: The roles and limitations of certification. Retrieved from Washington, DC
5. Baur, J. W., Tynon, J. F., Ries, P., & Rosenberger, R. S. (2014). Urban parks and attitudes about ecosystem services: does park use matter? Journal of Park and Recreation Administration, 32(4).