Additional resources
Snyder, C. R., Harris, C., Anderson, J. R., Holleran, S. A., Irving, L. M., Sigmon, S. T., et al. (1991). The will and the ways: Development and validation of an individual-differences measure of hope. Journal of Personality and Social Psychology, 60, 570-585.
Bigony, C. (2019). 15Five: Technology aligned to the science of thriving. (Unpublished master's thesis). University of Pennsylvania, Philadelphia, PA, USA.